What's New in 2001

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31 December 2000

    Happy and safe festive season to you all - good health and good coning in 2002 :

29 December 2001

    Ziconotide and cancer pain:
    The Program Abstracts for the 2001 Annual Meeting of the American Society of Clinical Oncology lists two presentations presenting results on the use of Ziconotide (based on omega-conotoxin MVIIA from Conus magus) for the treatment of intractable neuropathic pain.

    Lynn Webster, Raymond R Gaeta, Michael S. Leong and David Ellis (2001) "Ziconotide Efficacy in Patients with Chronic Intractable Pain of Malignant Origin: Efficacy as a Function of Patient Characteristics." ASCO Abstract #1550-2001 ,
    Alpine Medical, Salt Lake City, UT; Stanford University School of Medicine, Stanford, CA; and Elan Pharmaceuticals, Inc., South San Francisco, CA.
    Abstract: Pain is a common and devastating symptom of cancer, occurring in 33% of patients during treatment and in 75-90% of advanced cases. Nearly 75% of cancer patients report moderate/severe pain, yet less than half receive adequate analgesic therapy. Ziconotide, a synthetic peptide derived from the venom of predatory marine snails, is a specific blocker of neuronal N-type calcium channels. Efficacy and safety was evaluated in a double blind, placebo-controlled trial. Eligible patients (n=112) had pain secondary to cancer (88%) or AIDs (12%). Common cancer diagnoses included breast (25%), lung (16%) and colon (12%); 43.5% of cancer patients had metastatic disease while the remainder had pain secondary to localized disease. Baseline pain intensity was moderate to severe (mean VASPI 7.8); VASPI scores improved 53% for ziconotide vs. 18% for placebo, with 73% of ziconotide patients satisfying responder criteria (30% improvement in VASPI) compared to 30% placebo. The degree of improvement with ziconotide was unaffected by age or sex, and was slightly higher for cancer (55% ziconotide, 18% placebo) vs. AIDs (44% ziconotide, 22%placebo). Mean % VASPI improvement was also unaffected by metastatic status; patients with or without metastatic disease had equivalent responses. Patients with or without prior IT morphine (ITM) experience also responded equally well to ziconotide; placebo patients with ITM experience showed slightly better responses. Ziconotide is effective in a large proportion of patients with intractable pain of malignant origin. Efficacy is robust and not affected by patient demographics or disease status; patients with AIDS may respond less than patients with cancer, but patients unresponsive to IT morphine may benefit from ziconotide therapy. These data support ziconotide as a novel, and effective non-opioid alternative to intrathecal or systemic morphine in patients with chronic pain secondary to a wide range of malignancies. This research was sponsored by Elan Pharmaceuticals, Inc.

    Michael S. Leong, Lynn R Webster, David Ellis and Raymond R Gaeta (2001) "Identification of an Effective and Well-Tolerated Dose Range for Ziconotide, a Novel Non-Opioid Anlgesic for Chronic Pain". ASCO Abstract #1550-2001 ,
    Stanford University-School of Medicine, Stanford, CA; Pain and Stress Medicine Institute, Salt Lake City, UT; Elan Pharmaceuticals, Inc., South San Francisco, CA.
    Abstract: Serious pain is a common symptom of cancer, occurring in 20-50% of newly diagnosed and 75-90% of advanced cases. Opioid therapy for pain is often associated with serious side effects. Ziconotide, a synthetic peptide derived from the venom of predatory marine snails, specifically blocks neuronal N-type calcium channels. It represents an alternative to opioids for the treatment of chronic pain. Evaluated in a double-blind, placebo-controlled trial in patients (N=112) with chronic pain secondary to cancer or AIDS, ziconotide was given intrathecally (IT) to patients with moderate-severe pain intensity (measured on the VASPI scale, pain was scored 73.6/100mm for ziconotide vs. 77.9/100mm for placebo, where 100 mm = worst possible pain and 0 mm = least possible pain). Dose-related efficacy observed a pilot trial was used to develop an initial dosing schedule for the controlled trial: initial infusion rate (0.4 mcg/hr) was titrated q12 hrs over 5-6 days to 21.0 mcg/hr. This dosing regimen was subsequently reduced in response to adverse events, to yield an effective and well-tolerated regimen: dose of 0.1 mcg/hr titrated as needed for efficacy q24 hr over 5-6 days, to a maximum of 2.4 mcg/hr. The endpoint %VASPI improvement was slightly higher for the high-rate group (64.1%) than the low-rate group (44.1%). Regardless of initial starting dose, patients tended to show efficacy at doses [greater than or equal to] 0.3 mcg/hr. Common (10%) adverse events were reduced and generally reversible with the low rate regimen, indicating improved tolerability with maintenance of effectiveness. The final regimen was: initiate IT infusion at 0.1 mcg/hr, increasing to 0.2, 0.3, 0.6, 1.2 and 2.4 mcg/hr over 6 days. This dose range and regimen is safe and effective, producing significant analgesia in over 75% of patients treated, confirming ziconotide as an alternative to systemic or IT opioids. This research was sponsored by Elan Pharmaceuticals, Inc

    Confusion observed with Ziconotide:
    Lyn Webster, Robert Henderson, Nat Katz and David Ellis (2001) "Characterization of Confusion, An Adverse Event Associated with Intrathecal Ziconotide Infusion in Chronic Pain Patients" Pain Medicine 2001; 2 (3), 253-254.
    Ziconotide is a novel analgesic currently being developed for intrathecal (IT) infusion to patients with chronic, intractable pain. A long-term safety study has enrolled 586 patients who were titrated to efficacy and treated for up to 180 days. Confusion (COSTART term) is not infrequently observed with ziconotide IT infusion, and is frequently observed with opiates, so it was further characterized. Overall, confusion was observed in 34.3% of patients. Verbatim terms used to describe the observation were fogginess, spaciness, decreased mental alertness, disorientation to time, or mixed up feeling. Confusion occurred with an (mean ± SD) IT infusion rate of 0.30 ± 0.25 (median 0.225) mg/hr (recommended initial IT infusion rate is 0.10 mg/hr). An integrated summary of safety analysis, including trials that forced titration to rates of up to 7.0 mg/hr, revealed that higher IT infusion rates were associated with an increased incidence of all adverse events (AEs), including confusion. In the long-term safety study, the average time to onset of confusion was 49 ± 52 (median 31) days; it was intermittent in 66% and continuous in 31%. Confusion was judged to be severe in 17% of cases; the decision was made to reduce the dose in 49% and discontinue the infusion in 19% of cases. Confusion represented 3.9% of all serious AEs, defined as life-threatening or requiring hospitalization. It occurred with increased frequency when CNS depressants were administered concomitantly. The median confusion duration was 6 days, but resolved within 1 day in 1/3 of patients. It is believed to result from supraspinal distribution of ziconotide, occurs at therapeutic IT doses, is reversible, apparently dose-dependent, mild or moderate in most cases, and does not require cessation of therapy. [This long-term safety study is ongoing and presently enrolling patients; these results will be updated based on a larger dataset at the time of presentation.]

    History of Ziconotide:

  • Prous Science featured Ziconotide as its "Molecule of the Month" for July 2001.
  • The Stanford Magazine, Sept/Oct 2001 gave a brief report on Ziconotide entitled "Now, Snails Aren't Such a Pain"
  • TIME PACIFICJanuary 15, 2001 | NO. 2 feature article on "Potions from Poisons" - Looking for new drugs in unusual places" by ANDREA DORFMAN provided a vignette on cone shell toxins and their pharmaceutical applications.
  • The history of the development of Ziconotide is annotated at the BioSpace web site.
  • The following summary history of Ziconotide appears on the Cognetix Inc. web site : "In December 1999, Elan Corporation plc filed a new drug application (NDA) for ziconotide to receive FDA marketing approval. An approvable letter from the FDA was received by Elan in June 2000. Ziconotide is an w-conopeptide discovered in the University of Utah laboratory of Dr. Olivera. Ziconotide has been developed for the treatment of malignant and neuropathic pain, again employing the Medtronic SynchroMed® infusion system to facilitate intrathecal delivery. In 1998 Elan purchased Neurex Corporation for $740 million in order to acquire the rights to ziconotide".

24 December 2001

19 December 2001

    Cone Shell Images:
    ATLANTIC worldwide specimen shells, P.O.Box 4136, 4461-901 Sª Hora, PORTUGAL, have some nice images of cone shells from Nicobar Is., Taiwain, the Canary Islands and Columbia. Included are:
    Conus betulinus Linné, 1758 +65mm F++/F+++ Very special population, few, very fresh, Nicobar Is. Conus oishii Shikama, 1977, 33.2mm GEM Very rare, few in private collections, this one exceptional, Taiwan Conus siamensis Hwass, 1792, 93mm GEM(-) Beautiful, hard to get this quality, Canary Is. Conus siamensis Hwass, 1792, 120mm F+++ Very fresh and nice, hard to get this size, Canary Is. Conus ( velaensis) complex +31mm F+/F++ Few more just arrived, top color, can't identify precisely, Colombia

17 December 2001

16 December 2001

15 December 2001

14 December 2001

12 December 2001

    Novel recognition site for gamma carboxylation of propeptides:
    Nirmala Pudota, Eric Hommema, Kevin Hallgren, Beth McNally, Susan Lee and Kathleen Berkner from the Department of Molecular Cardiology, Lerner Research Institute and the Jacobs Center for Thrombosis and Vascular Biology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, have identified a second tethering site for carboxylase and vitamin K-dependent proteins (such as the conantokins) that is required for carboxylase activity.
    Pudota,B.N., Hommema,E.L., Hallgren,K.W., McNally,B.A., Lee,S. and Berkner, K.L. (2001) Identification of Sequences within the gama-Carboxylase That Represent a Novel Contact Site with Vitamin K-dependent Proteins and That Are Required for Activity. J. Biol. Chem., 276: 46878-46886
    Abstract: The vitamin K-dependent (VKD) carboxylase converts clusters of Glu residues to gamma-carboxylated Glu residues (Glas) in VKD proteins, which is required for their activity. VKD precursors are targeted to the carboxylase by their carboxylase recognition site, which in most cases is a propeptide. We have identified a second tethering site for carboxylase and VKD proteins that is required for carboxylase activity, called the vitamin K-dependent protein site of interaction (VKS). Several VKD proteins specifically bound an immobilized peptide comprising amino acids 343-355 of the human carboxylase (CVYKRSRGKSGQK) but not a scrambled peptide containing the same residues in a different order. Association with the 343-355 peptide was independent of propeptide binding, because the VKD proteins lacked the propeptide and because the 343-355 peptide did not disrupt association of a propeptide factor IX-carboxylase complex. Analysis with peptides that overlapped amino acids 343-355 indicated that the 343-345 CVY residues were necessary but not sufficient for prothrombin binding. Ionic interactions were also suggested because peptide-VKD protein binding could be disrupted by changes in ionic strength or pH. Mutagenesis of Cys343 to Ser and Tyr345 to Phe resulted in 7-11-fold decreases in vitamin K epoxidation and peptide (EEL) substrate and carboxylase carboxylation, and kinetic analysis showed 5-6-fold increases in Km values for the Glu substrate. These results suggest that Cys343 and Tyr345 are near the catalytic center and affect the active site conformation required for correct positioning of the Glu substrate. The 343-355 VKS peptide had a higher affinity for carboxylated prothrombin (Kd = 5 µM) than uncarboxylated prothrombin (Kd = 60 µM), and the basic VKS region may also facilitate exiting of the Gla product from the catalytic center by ionic attraction. Tethering of VKD proteins to the carboxylase via the propeptide-binding site and the VKS region has important implications for the mechanism of VKD protein carboxylation, and a model is proposed for how the carboxylase VKS region may be required for efficient and processive VKD protein carboxylation.

4 December 2001

    Novel omega-conotoxin from Conus consors:
    Dr. Favreau and colleages from France, report on a novel omega-conotoxin (omega-Ctx CNVIIA) from Conus consors collected in New Caledonia. This conopeptide consists of 27 amino acid residues folded by 3 disulfide bridges and has an unusual sequence (SSSKGR) in loop 4. It exhibits selectivity for N-type voltage sensitive calcium channels (VSCCs) versus P/Q-type VSCCs and provides a new tool for blocking these channels.
    Favreau, P., Gilles, N., Lamthanh, H., Bournaud, R., Shimahara, T., Bouet, F., Laboute, P., Letourneux, Y., Menez, A., Molgo, J. and Le Gall, F. (2001)" A New omega-Conotoxin That Targets N-Type Voltage-Sensitive Calcium Channels with Unusual Specificity".Biochemistry 40: 14567-14575.
    Abstract: A new specific voltage-sensitive calcium channel (VSCC) blocker has been isolated from the venom of the fish-hunting cone snail Conus consors. This peptide, named omega-Ctx CNVIIA, consists of 27 amino acid residues folded by 3 disulfide bridges. Interestingly, loop 4, which is supposed to be crucial for selectivity, shows an unusual sequence (SSSKGR). The synthesis of the linear peptide was performed using the Fmoc strategy, and the correct folding was achieved in the presence of guanidinium chloride, potassium buffer, and reduced/oxidized glutathione at 4 degrees C for 3 days. Both synthetic and native toxin caused an intense shaking activity, characteristic of omega-conotoxins targeting N-type VSCC when injected intracerebroventricularly to mice. Binding studies on rat brain synaptosomes revealed that the radioiodinated omega-Ctx CNVIIA specifically and reversibly binds to high-affinity sites with a K(d) of 36.3 pM. Its binding is competitive with omega-Ctx MVIIA at low concentration (K(i) = 2 pM). Moreover, omega-Ctx CNVIIA exhibits a clear selectivity for N-type VSCCs versus P/Q-type VSCCs targeted respectively by radioiodinated omega-Ctx GVIA and omega-Ctx MVIIC. Although omega-Ctx CNVIIA clearly blocked N-type Ca(2+) current in chromaffin cells, this toxin did not inhibit acetylcholine release evoked by nerve stimuli at the frog neuromuscular junction, in marked contrast to omega-Ctx GVIA. omega-Ctx CNVIIA thus represents a new selective tool for blocking N-type VSCC that displays a unique pharmacological profile and highlights the diversity of voltage-sensitive Ca(2+) channels in the animal kingdom.

3 December 2001

    Chilean Sea Shells:
    Conchas y Carcoles de Chile / Chilean Sea Shells provides help for identification and knowledge of Chilean shells for amateurs of this great hobby. Included is an image of the following cone shell - Conus miliaris, Rehder, 1980 , 2.5 cms, Easter Island.

27 November 2001

26 November 2001

24 November 2001

23 November 2001

    Novel Contryphan-Vn from Conus ventricosus :
    Drs Massilia, Schinina, Ascenzi and Polticelli from the Department of Biology, University "Roma Tre,", Rome, Italy, have extracted a novel contryphan from the venom of the Mediterranean cone shell, Conus ventricosus, (also known as Conus mediterraneus).
    Massilia GR, Schinina ME, Ascenzi P, Polticelli F. (2001) Biochem Biophys Res Commun 288: 908-913
    Abstract: The isolation, purification, and biochemical characterization of the novel peptide Contryphan-Vn, extracted from the venom of the Mediterranean marine snail Conus ventricosus, is reported. Contryphan-Vn is the first Conus peptide described from a vermivorous species and the first purified from the venom of the single Mediterranean Conus species. The amino acid sequence of Contryphan-Vn is As with other contryphans, Contryphan-Vn contains a d-tryptophan residue, is amidated at the C-terminus, and maintains the five-residue intercystine loop size. However, Contryphan-Vn differs from the known contryphans by the insertion of the Asp residue at position 2, by the lack of hydroxylation of Pro(4), and, remarkably, by the presence of the basic residue Lys(6) within the intercystine loop. Although the biological function(s) of contryphans is still unknown, these characteristics suggest distinct molecular target(s) and/or function(s) for Contryphan-Vn.

18 November 2001

15 November 2001

    "Seas of Promise" - Update on COGNETIX Inc.
    Rob Jones, of COGNETIX INC.has brought to my attention an article by Bob Mims in the Salt Lake City Tribune of 11 November, 2001, providing an update on COGNETIX Inc. and describing progress they are making with the development of medicines from cone snail venom components. "One, CGX-1007 (conantokin-G) could reduce or eliminate heretofore untreatable epileptic seizures; another compound, CGX-1160 (contulakin-G), shows promise in relieving post-operative pain...and CGX-1002 (a selective sodium channel blocker) is a long-acting local anesthetic thought especially effective against corneal and burn pain.. (and).. another snail venom product CGX-1204, (in preclinical trials)... has shown promise as a muscle relaxer with potential use in easing emergency room insertion of tracheal airway devices". Click here to see how a conus snail eats its prey.
    [Source: "Seas of Promise" - by Bob Mims published in Salt Lake City Tribune, 11 November, 2001].

14 November 2001

    Conantokins antagonise the NMDA receptor
    Klein, R.C., Warder, S.E., Galdzicki, Z., Castellino, F.J. and Prorok, M. (2001) Kinetic and mechanistic characterization of NMDA receptor antagonism by replacement and truncation variants of the conantokin peptides. Neuropharmacology. 41: 801-810.
    Abstract: The characterization of conantokin-T (con-T), conantokin-R (con-R), and variants thereof, using the whole-cell patch clamp technique, was undertaken to evaluate the contribution of various residues towards the onset and recovery of N-methyl-D-aspartate (NMDA) receptor inhibition in cultured embryonic murine hippocampal neurons. The results obtained indicate that the two most C-terminal gamma-carboxyglutamic acid (Gla) residues of the conantokins, while not essential for activity, provided for more tenacious binding to the receptor. Specifically, con-T[gamma10K/gamma14K] and con-R[gamma11A/gamma15A] displayed 5.6- and 8.4-fold decreases in tau(off), respectively, compared to the parent peptides. For the truncated con-T variants, con-T[1-9/Q6G], and a sarcosine (Src)-containing species, con-T[1-9/G1Src/Q6G], the tau(off) was over 80- and 40-fold faster, respectively, compared to con-T. For the latter peptide, the coapplication of 300&mgr;M spermine enhanced the onset rate constant from 3.1x10(3)M(-1)s(-1) to 12.6x10(3)M(-1)s(-1). From analysis of equilibrium dose-inhibition curves using the Cheng-Prusoff equation, a K(i) value of 1.1&mgr;M for the peptide was obtained. Con-T[1-9/G1Src/Q6G] demonstrated an apparent competitive mode of inhibition relative to NMDA. Schild analysis of the data yielded an equilibrium dissociation constant of 2.4&mgr;M for the interaction of con-T[1-9/G1Src/Q6G] with the receptor.

13 November 2001

    Update on "Conus hayesi"
    Werner Korn announced a name change for Conus hayesi Korn 2000 mentioned below (9 November entry). Writing in La Conchiglia 299: page 18, he commented that there is already a fossil cone named hayesi (C. hayesi Arnold 1909) from California. As the intended new species from South Africa was named after Brian Hayes, it was appropriate to use the replacement name Conus brianhayesi Korn 2001 for this new species. Thanks are due to Arnold Zandbergen, The Netherlands, for bringing this to my notice.

12 November 2001

    Exceptional Shells
    Guido Poppe has announced a web site featuring Exceptional Shells. According to Guido, "They are exceptional for at least one reason, or a combination of these reasons. Criteria can be extreme rarity. More beautiful than usual. Unusual locality. Giant sizes or World Record Sizes. A very particular family. Unusual colors. a/o. Prices have nothing in common with normal shells, and you can inquire for their price by e-mail if interested to acquire one or more of the EXCEPTIONAL SHELLS. All specimens come with a certificate in color, on which you will find a print in color of the image that you view now, the text, particular for each species, and your name." Click here for a fast-link to Exceptional CONIDAE.

    Philippines Shells:
    Emanuel GUILLOT DE SUDUIRAUT has updated his Shells of Philippines site with 12 new Cone Shells.
    Conus consors Sowerby I, in Sowerby II, 1833 color form, Panglao isl.; Conus pergrandis (Iredale, 1937) 161.5 mm. Balut isl. 250 m.; Conus distans Hwass in Bruguière, 1792, 97 mm. Calituban isl. Conus eburneus Hwass, in Bruguière, 1792, 73 mm. Zamboanga Sulu sea ; Conus floridulus Adams & Reeve, 1848, Balicasag isl. 140 m.; Conus glaucus Linnaeus, 1758, Aliguay isl. ; Conus mitratus Hwass, in Bruguière, 1792 34 mm. Laminusa isl. Sulu sea; Conus mustelinus Hwass, in Bruguière, 1792 Mactan isl.; Conus omaria Hwass, in Bruguière, 1792, 91 mm. Palawan isl.; Conus pulicarius Hwass, in Bruguière, 1792 62 mm. Calituban isl. ; Conus stupella (Kuroda, 1956), 64 mm. Balut isl., and Conus thalassiarchus Sowerbi I in Sowerby II, 1834, 90 mm. Zamboanga Sulu sea.

9 November 2001

    Xenome Ltd. to develop chi-conopeptides for treatment of pain
    In a media release, Xenome Limited, a Queensland-based biopharmaceutical R&D company announced (Friday 9 November, 2001) the discovery of a novel family of molecules with significant potential for the treatment of pain conditions. The chi-conopeptides (see entry for 9 September, below to article by Sharpe, I.A. et al in Nature Neuroscience 4: 902-907, 2001) were discovered by the Venom Research Group at the Institute for Molecular Bioscience at The University of Queensland, in a project led by Dr Richard Lewis and Professor Paul Alewood. "The chi molecules, and related derivatives, have shown analgesic properties in animal model trials that measure efficacy against neuropathic and inflammatory pain," said Dr Drinkwater, Head of Research and a co-founder of Xenome Ltd. In a second media release, the company announced that it had successfully raised AUD$4.5m from a new share issue. "This investment will enable the company to forge ahead with its established drug discovery program and further develop its drug candidates." said Dr Tony Evans, CEO of Xenome.

    New species of Conus confirmed
    *[Conus hayesi Korn, 2001]- (La Conchiglia 297: 15) - Shell up to 25 mm in length; protoconch of about 1.75 whorls, maximum diameter 1.5-1.6 mm. Ground color white to cream, base stained with brown or violet brown; basic color pattern of last whorl composed of brown spiral elements: spiral lines and/or spiral rows of dashes extending from base to shoulder. Very similar to C. bairstowi Sowerby III. However, the latter grows to 44 mm. Moreover, subadult shells of C. bairstowi differ from similarly sized C. hayesi in their usually narrower last whorl and in their generally higher spire; the spire outline of C. bairstowi tends to be concave or straight, whereas it is rather straight to convex in C. hayesi; the surface sculpture of last whorl is more pronounced, but finer, in C. bairstowi . Type locality: off Transkei, South Africa, in 80-100 m.. [Source: http://coa.acnatsci.org/conchnet/n-cone.html]
    Click here for Images of Conus hayesi.
    See entry for 14 May 2000.
    *NOTE: see announcement of name change above (entry 13 November, 2001). This species now to be known as Conus brianhayesi Korn 2001 (La Conchiglia 299: 18)

6 November 2001

4 November 2001

    Columbian, Mozambique and Indonesian Cones:
    ATLANTIC worldwide specimen shells, P.O.Box 4136, 4461-901 Sª Hora, PORTUGAL, have some nice images of cone shells from Columbia, Mozambique , Indonesia and the Philippines. Included are:
    Conus rosalindensis, Petuch, 1995 [+15mm F++/GEM Rare, only two, for specialist]; Conus rosalindensis, Petuch, 1995 [20,1mm GEM(-) Another with exceptional size]; Conus sanctaemarthae, Vink, 1977 [70,1mm F+++ Outstanding shell, monster size, high quality]; Conus vikingorum, Petuch, 1992 [+35mm F++/GEM Rare and outstanding, top color, only two]; Conus guajira Petuch, 41,5mm F++ Very rare, another beautiful shell, only one, Colombia 85; Conus julieandreae Cargille, 1995 +19mm F++/F+++ Rare, big size for the species, very seldom seen, E. Honduras 70; Conus sanctaemarthae Vink, 1977 60,5mm Outstanding, giant size, beautiful shell, Colombia 85; Conus sp. +27mm F++/F+++ Can't identify, deep water, for specialist, Colombia 45; Conus sp. 30,5mm GEM Rare, very unusual shell, for specialist, Colombia 60; Conus phlogopus Tomlin, 1937 +65mm F++/GEM, spectacular shells, Colombia; Conus sp. +20mm F++/GEM Rare, probably C. velaensis, for specialist, Colombia; Conus spurius Gmelin, 1791 +48mm F++/GEM Very special "orange" form, natural, live taken, Colombia; Conus baeri Röckel & Korn, 1992 39.8mm GEM Very rare, exceptional shell, deep water, Mozambique; Conus victor Broderip, 1842, 34mm GEM Rare, "golden" form, now very hard to get, beautiful shell, Indonesia; Conus ebraeus Linné, 1758 +41mm F+/F++ Outstanding size and color, only two, Philippines; Conus euetrios Sowerby, 1882 +60mm F++/GEM Outstanding quality and deep blue color, Mozambique; Conus paulae Petuch, 1988 +22mm F++/F+++ Rare, trawled specimen, seldom seen, Colombia; and Conus spirofilis Habe & Kosuge, 1970 +22mm F++/GEM Rare, superb little shells, few only, Philippines.

3 November 2001

    Delta-Conotoxin family :
    Dr. Greg Bulaj and colleagues from the Departments of Biology and Pathology, University of Utah, Salt Lake City, Utah 84112, and Department of Pediatrics, Oregon Health Sciences University, Portland, Oregon 97201, have applied a cladistic analysis to identify amino acids critical for the activity of conotoxins.
    Bulaj, G., De La Cruz, R., Azimi-Zonooz, A., West, P., Watkins, M., Yoshikami, D. and Olivera, B.M.(2001)"delta-Conotoxin Structure/Function through a Cladistic Analysis".Biochemistry 40 :13201-13208.
    Abstract: delta-Conotoxins are Conus peptides that inhibit inactivation of voltage-gated sodium channels. The suggestion that delta-conotoxins might be an essential component of the venoms of fish-hunting cone snails which rapidly immobilize their prey [Terlau, H., Shon, K., Grilley, M., Stocker, M., Stuhmer, W., and Olivera, B. M. (1996) Nature 381, 148-151] has not been tested. On the basis of cDNA cloning, all of the fish-hunting Conus analyzed yielded at least one delta-conotoxin sequence. In addition, one delta-conotoxin isolated from the venom of Conus striatus had an amino acid sequence identical to that predicted from cDNA cloning. This new peptide exhibited properties of delta-conotoxins: it targeted sodium channels and potentiated action potentials by slowing channel inactivation. Homologous sequences of delta-conotoxins from two groups (clades) of related fish-hunting Conus species share consensus features but differ significantly from the two known delta-conotoxins from mollusc-hunting Conus venoms. Three large hydrophobic amino acids were conserved; analogues of the previously described delta-conotoxin PVIA with alanine substituted for the conserved amino acids F9 and I12 lost substantial biological activity. In contrast, both the T8A and K13A delta-conotoxin PVIA analogues, where substitutions were at nonconserved loci, proved to be biologically active. Taken together, our results indicate that a cladistic approach can identify amino acids critical for the activity of conotoxins and provide extensive information as to which amino acid substitutions can be made without significant functional consequences.

2 November 2001

    Searchable Invertebrate Reproduction Database :
    The Kewalo Marine Laboratory at the Pacific Biomedical Research Centre, University of Hawaii, has established a searchable Invertebrate Reproducton Database (supported by the National Science Foundation), containing phylogenetic and reproductive information about the reproduction and development of a number of Hawaiian marine species. The tabular HTML output of the search engine can be saved and imported directly into a spreadsheet or database program(e.g. Microsoft Excel or Access). Included in this searchable database is information on the following 21 species of the genus Conus - (Enter [Searchfield = genus] [Keyword = Conus], then Submit) : C. abbreviatus, C. catus, C. ebraeus, C. flavidus, C. hebraeus, C. imperialis, C. leopardus, C. lividus, C. nanus, C. obscurus, C. obscurus, C. pennaceus, C. perthusus, C. pertusus, C. pulicarius, C. quercinus, C. rattus, C. sponsalis, C. striatus, C. textile, C. vexillum and C. vitulinus. Fields included in the database are Phylum, Class, Order, Family, Genus, Species, Reproduction Method, Egg Diameter, Reproductive Season, Development, Occurrence and References.
    Two key references in this area of research are : Frank E. Perron in "The Reproductive Ecology of Conus in Hawaii, 1981"; and 2) J.B. Taylor in "Planktonic Prosobranch Veligers of Kaneohe Bay"
    - Also see two articles by Frank E. Perron in the Internet Hawaiian Shell News (IHSN), March 1998 "Laboratory Culture of Conus Textile" and "Larval Growth and Metamorphosis of Conus", and two articles by Wes Thorsson about Frank's work, one in IHSN, March 1998 "Veliger and Larval Conus Shells of Hawaii - A summary of a paper by Frank E. Perron, Summarized by Wesley Thorsson with additional observations."; and the other by Wes Thorrson in June 1999 IHSN, "Juvenile Molluscs", from which the following is taken:
    "In prior issues of IHSN (9803 and 9804), we have presented research results of Frank Perron in raising Conus species from eggs and his thorough details about the growth of Conus pennaceus .... This type of research is extremely time consuming, but can produce extremely valuable basic information. Perron kept records on C. pennaceus specimens in one area over a number of years, and produced an amazing amount of data. By plotting the frequency of occurrence of a discrete shell lengths at a number of times, he could display a group of the specimens growing with time, due to the fact that this species tends to lay eggs at one season in that area. All in a range of lengths would be one year group. Perron also raised a batch of eggs from a specimen that had been called C. ellisae Kiener, 1845 due to its very different color pattern.. Since we had seen some specimens that had changed from a typical pattern to the “C. ellisae pattern” in a single whorl, we were sure these were actually C. pennaceus. Perron proved this when both patterns were found on the shells that hatched from a single egg case".

    Another article of interest by Frank Perron is in the April 1998 issue of IHSN and is on the growth of Conus pennaceus. Entitled GROWTH, FECUNDITY, AND MORTALITY OF CONUS PENNACEUS IN HAWAII this article describes the early development of Conus pennaceus.
    Back Issues of IHSN above are not available     on line, but can be obtained on CD by emailing Wes Thorsson with your mail address. CDs are priced at $12.00 for U.S. addresses or $15.00 for non-U.S. addresses payable to Wesley Thorsson, 122 Waialeale St., Honolulu, Hawaii 95825-2020 No credit cards available. [$8.00 goes to the HMS Scholarship fund, the rest to expenses]. Prices are reduced for multiple CDs on the same order.

30 October 2001

    South African Cone Shells:
    Alwyn Marais, from South Africa, has posted 12 images of cone shells on a new shell site, SA Shells that concentrates on the South African region primarily. Included are Conus mozambicus, Conus natalis gilchristi, Conus orbignyi elokismenos, Conus pictus, Conus simplex, Conus tinianus and Conus zulu. There are also some shell books by Prof. Doug Steyn and other shelling items will come on line in the near future.

    Conantokin interaction with NMDA receptor:
    Drs Wittekindt and colleagues from the Department of Neurochemistry, Max-Planck-Institute for Brain Research, Deutschordenstrasse 46, 60528, Frankfurt/Main, Germany, have used homology-based molecular modeling to suggest how Conantokin-G (from Conus geographus) interacts with the NMDA receptor.
    Wittekindt, B., Malany, S., Schemm, R., Otvos, L., Maccecchini, M.L., Laube, B. and Betz, H. (2001) Point mutations identify the glutamate binding pocket of the N-methyl-D-aspartate receptor as major site of Conantokin-G inhibition. Neuropharmacology 41: 753-761.
    Abstract: Conantokin-G (Con-G), a gamma-carboxylglutamate (Gla) containing peptide derived from the venom of the marine cone snail Conus geographus, acts as a selective and potent inhibitor of N-methyl-D-aspartate (NMDA) receptors. Here, the effect of Con-G on recombinant NMDA receptors carrying point mutations within the glycine and glutamate binding pockets of the NR1 and NR2B subunits was studied using whole-cell voltage-clamp recording from cRNA injected Xenopus oocytes. At wild-type receptors, glutamate-induced currents were inhibited by Con-G in a dose-dependent manner at concentrations of 0.1-100 &mgr;M. Substitution of selected residues within the NR2B subunit reduced the inhibitory potency of Con-G, whereas similar mutations in the NR1 subunit had little effect. These results indicate a selective interaction of Con-G with the glutamate binding pocket of the NMDA receptor. Homology-based molecular modeling of the glutamate binding region based on the known structure of the glutamate binding site of the AMPA receptor protein GluR2 suggests how selected amino acid side chains of NR2B might interact with specific residues of Con-G.

    Conantokin selectivity at NMDA receptor:
    Drs Klein and colleagues from the Department of Chemistry and Biochemistry and the W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana 46556, USA. have examined the subunit selective antagonism of conantokins for the NMDA receptor.
    Klein, R.C., Prorok, M., Galdzicki, Z. and Castellino, F.J. (2001) The amino acid residue at sequence position 5 in the conantokin peptides partially governs subunit-selective antagonism of recombinant N-methyl-D-aspartate receptors. J Biol Chem. 276:26860-26867.
    Abstract: Whole cell voltage clamp recordings were performed to assess the ability of conantokin-G (con-G), conantokin-T (con-T), and a 17-residue truncated form of conantokin-R (con-R[1-17]) to inhibit N-methyl-d-aspartate (NMDA)-evoked currents in human embryonic kidney 293 cells transiently expressing various combinations of NR1a, NR1b, NR2A, and NR2B receptor subunits. Con-T and con-R[1-17] attenuated ion currents in cells expressing NR1a/NR2A or NR1a/NR2B. Con-G did not affect NMDA-evoked ionic currents in cells expressing NR1a/NR2A, but it showed inhibitory activity in cells expressing NR1a/NR2B receptors and the triheteromeric combination of NR1a/NR2A/NR2B. An Ala-rich con-G analog, con-G[Q6G/gamma7K/N8A/gamma10A/gamma14A/K15A/S16A/N17A] (Ala/con-G, where gamma is Gla), in which all nonessential amino acids were altered to Ala residues, manifested subunit specificity similar to that of con-G, suggesting that the replaced residues are not responsible for selectivity in the con-G framework. A sarcosine-containing con-T truncation analog, con-T[1-9/G1Src/Q6G], inhibited currents in NR1a/NR2A and NR1a/NR2B receptors, eliminating residues 10-21 as mediators of the broad subunit selectivity of con-T. In contrast to the null effects of con-G and Ala/con-G at a NR1a/NR2A-containing receptor, some inhibition ( approximately 40%) of NMDA-evoked currents was effected by these peptides in cells expressing NR1b/NR2A. This finding suggests that the presence of exon 5 in NR1b plays a role in the activity of the conantokins. Analysis of various conantokin analogs demonstrated that Leu(5) of con-G is an important determinant of conantokin selectivity. Taken as a whole, these results suggest that the important molecular determinants on conantokins responsible for NMDA receptor activity and specificity are discretely housed in specific residues of these peptides, thus allowing molecular manipulation of the NMDA receptor inhibitory properties of the conantokins.

25 October 2001

    Solution conformation of alpha-conotoxin EI:
    Park, K.H., Suk, J.E., Jacobsen, R., Gray, W.W., McIntosh, J.M. and Han, K.H. (2001) "Solution conformation of alpha-conotoxin EI, a neuromuscular toxin specific for the alpha{sub1}/{delta} subunit interface of torpedo nicotinic acetylcholine receptor". J Biol Chem. Oct 18 [epub ahead of print]

    Abstract: A high-resolution structure of alpha-conotoxin EI has been determined by (1)H NMR spectroscopy and molecular modeling. alpha-Conotoxin EI has the same disulfide framework as alpha4/7 conotoxins targeting neuronal nicotinic acetylcholine receptor, but antagonizes neuromuscular receptor as alpha3/5 and alphaA conotoxins. The unique binding preference of alpha-conotoxin EI to the alpha(1)/delta subunit interface of Torpedo neuromuscular receptor makes it a valuable structural template for superposition of various alpha-conotoxins possessing distinct receptor subtype specificities. Structural comparison of alpha-conotoxin EI with the gamma-subunit favoring alpha-conotoxin GI suggests that the Torpedo delta-subunit preference of the former originates from its second loop. Superposition of three-dimensonal structures of seven alpha-conotoxins reveals that the estimated size of the toxin-binding pocket in nicotinic acetylcholine receptor is ~ 20 (height) x 20 (width) x 15 (thickness).

    This study complements another, lower resolution, three-dimensional structure of a-conotoxin EI determined earlier by Aldo Franco and Frank Mari from Florida Atlantic University, Florida.
    See: Franco, A. and Mari, F. (1999) "Three-dimensional structure of a-conotoxin EI determined by 1H NMR spectroscopy". Letters in Peptide Science 6: 199-207.
    Abstract: a-Conotoxin EI is an 18-residue peptide (RDOCCYHPTCNMSNPQIC;4–10, 5–18) isolated from the venom of Conus ermineus, the only fish-hunting cone snail of the Atlantic Ocean. This peptide targets specifically the nicotinic acetylcholine receptor (nAChR) found in mammalian skeletal muscle and the electric organ Torpedo, showing a novel selectivity profile when compared to other a-conotoxins. The 3D structure of EI has been determined by 2D-NMR methods in combination with dynamical simulated annealing protocols. A total of 133 NOE-derived distances were used to produce 13 structures with minimum energy that complied with the NOE restraints. The structure of EI is characterized by a helical loop between Thr^9 and Met^12 that is stabilized by the Cys^4-Cys^10 disulfide bond and turns involving Cys^4-Cys^5 and Asn^14-Pro^15. Other regions of the peptide appear to be flexible. The overall fold of EI is similar to that of other a4/7-conotoxins (PnIA/B, MII, EpI). However, unlike these other a4/7-conotoxins, EI targets the muscular type nAChR. The differences in selectivity can be attributed to differences in the surface charge distribution among these a4/7-conotoxins. The implications for binding of EI to the muscular nAChR are discussed with respect to the current NMR structure of EI.

24 October 2001

    Drugs from the Sea - Book Review:
    David Craik from the Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia. (e-mail: d.craik@imb.uq.edu.au) has provided the following book review for Trends in Pharmacological Sciences, Volume 22, Issue 5, 1 May 2001, Page 261 under the by-line "Fishing for new drug leads". The book contains a chapter by Toto Olivera entitled "w-Conotoxin MVIIA: From MarineSnail Venom to Analgesic Drug".
    Drugs from the Sea
    edited by Nobuhiro Fusetani, Karger, Basel, 2000. US$ 121.00 (hardback) (vi +158 pages), ISBN 3 8055 7098 8
    "The hope that the sea would provide a rich new source of drugs or drug leads has been held for more than 30 years, since various symposia began to address this possibility in the 1960s. However, few such agents have progressed to the clinic. This book presents several chapters on the discovery, development and production of drugs from the sea. In the main, the contributing authors were participants at the Naito Conference on Chemical and Biological Basis for the Diversity of Marine Life, held in October 1997.
    A recurring theme of several chapters, and one that explains the so far relatively low success rate for marine drug candidates, is the ‘supply’ issue. Marine bioactive molecules are often only present in tiny amounts. The difficulty of obtaining sufficient materials for study, combined with their often complex structures, has undoubtedly contributed to marine natural products being under-represented in the world’s pharmacopoeia, relative to molecules from terrestrial sources. However, this book points to some promising signs for the future.
    The opening chapter identifies ten marine-derived molecules in clinical trial, including one, conotoxin MVIIA, that is soon expected to reach the market in the USA as a treatment for pain. Indeed, the chapter by Baldomera Olivera describing the discovery and development of this molecule, to be marketed as Ziconotide, was a pleasure to read. The story of how Michael McIntosh, who started as a research student with Olivera at the University of Utah before he even graduated from high school, became involved in the discovery of conotoxin MVIIA should provide inspiration to many young scientists. This molecule is, in fact, just one of dozens of peptide components typically found in the venoms of cone snails. Multiply this by the hundreds of known snail species and it becomes clear that there are potentially many more therapeutically useful molecules awaiting discovery. Snails use their venoms for the capture of prey but the potent ion-channel blocking ability of the conotoxins can also be harnessed for blocking the neurotransmission of pain responses. The adage that one man’s poison is another’s medicine certainly holds true in this case. Overall, this book provides a timely summary of current progress in the field of drugs from the sea".

23 October 2001

    Conantokins - structure function Review:
    Prorok, M. and Castellino, F.J. (2001) Structure-function relationships of the NMDA receptor antagonist conantokin peptides. Curr Drug Targets. 2: 313-322.
    Abstract: The three members of the conantokin peptide family identified to date are conantokin(con)-G, -T and -R. Their defining attributes include a high relative content of gamma-carboxyglutamic acid (Gla), N-terminal sequence identity, as well as considerable overall sequence homology, and antagonism of the N-methyl-D-aspartate receptor (NMDAR). As promising templates for the design of neuroprotective agents, a thorough evaluation of structure-function relationships in these peptides will be invaluable in aiding rational drug modeling. To this end, a comprehensive assessment of the contributions of individual residues to conantokin structure and function is required. The current review summarizes recent efforts in this area, and also includes the effects of peptide length, as well as structural-stabilization and -destabilization on the structural and inhibitory profiles of an extensive panel of conantokin derivatives.

22 October 2001

    Silver cone shells !!:
    For the cone shell collector who has the lot, here are two cone shells - from the collection of Cambodian Silver Shells available from the Amazing Grace Elephant Company, Limited in Hong Kong.

    Cone shells of Martinique:
    David Touitou has made a short iconography (unfinished yet) of conidiae he has collected at la Martinique island. Some pictures are of dead specimens because of their rarity. Take a look here at the article by Mr. Roger Le Beon. Included are Conus ambiguus, cacao, cloveri, equinophilus, erminius, genuanus, guinaicus, hybridus, mercator, pinaui, pulcher, unifasciatus and tabidus. Also at the seashell-collector site is a collection of images of Cone Shells from Martinique, (including rare and deepwater species) last updated 19 October, 2001. Included are Conus attenuatus, burryae, daucus, erminius, granulatus, mazei, mindanus, mus, punticulatus, pusillus, regius, riosi and spurius. (These are in addition to the finds of C. regius listed below on 20 August and 27 July, 2001).

    Conotoxin MII used to characterize nicotinic acetylcholine receptors in bovine chromaffin cells:
    Dr. Tachikawa and colleagues from the Department of Pharmacology, School of Medicine, Iwate Medical University, Uchimaru 19-1, 020-8505, Morioka, Japan, have used conotoxin MII (from Conus magus) in a pharmacological study to characterize the major nicotinic acetylcholine receptor subtypes responsible for catecholamine release from bovine chromaffin cells as most probably, a3b4 or a3b4a5.
    Tachikawa, E., Mizuma, K., Kudo, K., Kashimoto. T,, Yamato. S. and Ohta, S.(2001) "Characterization of the functional subunit combination of nicotinic acetylcholine receptors in bovine adrenal chromaffin cells." Neurosci Lett 312: 161-164
    Abstract: The combination of nicotinic acetylcholine receptors (nAChRs) subunits connecting with the secretion of catecholamines in bovine adrenal chromaffin cells was pharmacologically investigated using selective agonists and antagonists for their nAChRs. The EC(50) values (uM) for the agonists that stimulate the catecholamine secretion and the rank order were as follows: nicotine (3.3) >= 1,1-dimethyl-4-phenylpiperazinium (3.5) >(E)-N-methyl-4-(3-pyridinyl)-3-butene-1-amine (14) > cytisine (23) >= acetylcholine (25). However, because both the rank order and the EC(50) values differed considerably from those in the various subunits' combinations expressed in Xenopus oocytes or mammalian cells (e.g. alpha2beta2, alpha3beta4, alpha4beta4, etc.), we could not compare them. On the other hand, the IC(50) values (uM) for the antagonists that inhibit the secretion and the rank order were mecamylamine (0.08) > alpha-conotoxin-MII (alpha-CTX-MII) (0.71) > dihydro-beta-erythroidine (DHbetaE) (48) > alpha-bungarotoxin (alpha-BTX) (no effect). Mecamylamine is a highly selective antagonist for alpha3beta4 nAChRs, and alpha-CTX-MII and alpha-BTX are specific antagonists for alpha3beta2 and alpha7 nAChRs, respectively. DHbetaE is a selective antagonist for the alpha4beta2. It has already been shown that the mRNAs for alpha3, alpha5, alpha7 and beta4 subunits are expressed in the chromaffin cells. Therefore, the subunit combination of nAChRs associated with the catecholamine secretion from bovine adrenal chromaffin cells is suggested to be at least alpha3beta4 or alpha3beta4alpha5. Further, the results indicate that the utilization of the nicotinic agonists as selective ligands for the subunit combination of nAChRs may be not suitable for the characterization of nAChRs.

    From the archives: Cone shell envenomation video:
    TREATING PAIN: Synthetic snail venom may lead to new drugs produced by Heather Ross, reported by Lucky Severson, story by Shawn O’Leary, video edited by Katie Elfsten (source INN Health Surfing Report, Tuesday March 14, 2000; INNX / InterNetwork News. Copyright © 1999-2001)
    Cone snail envenomation - video REAL PLAYER Auto; Medium ; Large ; QUICK TIME Small ; Medium ; Large ; WINDOWS MEDIA PLAYER Small ; Medium ; Large .

    From the archives: Bob Endean (1925-1997):
    Dr. Bob Endean was one of the first to study the pharmacological effects of cone shell venom. A tribute to Bob Endean was presented on Radio Australia in February 1998. Bob Endean was a marine biologist and one of the pioneers of coral reef research. This obituary was published in Reef Encounter, the newsletter of International Society for Reef Studies, in Number 23, pp 9 – 11 in July 1998. An edited version, entitled ‘Eco-warrior of the Great Barrier Reef’, appeared in The Australian newspaper on 29 October 1997. A number of his publications on venomous cone shells are listed below:
    Endean R, Gyr P, Surridge J.(1979)The effects of crude venoms of Conus magus and Conus striatus on the contractile response and electrical activity of guinea-pig cardiac musculature. Toxicon. 17(4):381-95.
    Endean R, Gyr P, Surridge J. (1977) The pharmacological actions on guinea-pig ileum of crude venoms from the marine gastropods Conus striatus and Conus magus. Toxicon. 15(4):327-37.
    Endean R, Surridge J, Gyr P. (1977) Some effects of crude venom from the cones Conus striatus and Conus magus on isolated guinea-pig atria. Toxicon. 15(5):369-74.
    Endean R, Williams H, Gyr P, Surridge J. (1976) Some effects on muscle and nerve of crude venom from the gastropod Conus striatus. Toxicon. 14(4):267-74.
    Endean R, Parish G, Gyr P. (1974) Pharmacology of the venom of Conus geographus. Toxicon. 12(2):131-8.
    Endean R, Gyr P, Parish G. (1974) Pharmacology of the venom of the gastropod Conus magus. Toxicon. 12(2):117-29.
    Endean R, Duchemin C. (1967) The venom apparatus of Conus magus. Toxicon. 4(4):275-84.

16 October 2001

    Origins of cone shell toxin diversity:
    More on this intriguing topic in a recent paper by Olivera, Cruz and colleagues from the National Institute of Molecular Biology and Biotechnology, College of Science, University of the Philippines, Diliman, 1101, Quezon City, Philippines

    Espiritu DJ, Watkins M, Dia-Monje V, Cartier GE, Cruz LJ, Olivera BM. (2001) Venomous cone snails: molecular phylogeny and the generation of toxin diversity. Toxicon, 39: 1899-1916.
    Abstract: In order to investigate the generation of conotoxin diversity, delta-conotoxin sequences from nine Conus species were analyzed in the context of their phylogeny. Using a standard molecular marker, mitochondrial 16S RNA, we determined that the delta-conotoxins were derived from three distinct species clades based on the phylogenetic reconstruction of a large set (>80) of Conus species and other toxoglossate molluscs. Four different mechanisms appear to have contributed to the diversity of the delta-conotoxins analyzed: (1) Speciation: delta-Conotoxins in different species diverge from each other (the prepro regions of orthologous genes somewhat more slowly than the reference rRNA rate, the mature toxin regions significantly faster). (2) Duplication: Intraspecific delta-conotoxin divergence is initiated by gene duplication events, some of which may have predated the species itself. (3) Recombination: A novel delta-conotoxin may arise through recombination of two parental delta-contoxin genes. (4) 'Focal hypermutation': This sudden, almost saltatory change in sequence is always restricted to the mature toxin region.The first three have been recognized previously as mechanisms important for the evolution of gene families in other phylogenetic systems; the last is a remarkable, mechanistically unexplained and specialized feature of Conus peptide diversification.

    Interaction of mu-conotoxin GIIIA with Na channels:
    Dr. Nakamura and colleagues from the Graduate School of Bioagricultural Sciences, Nagoya University, Japan, have studied the role of Arg-13 in mu-conotoxin GIIIA in interactions with skeletal muscle sodium channels.
    Nakamura M, Niwa Y, Ishida Y, Kohno T, Sato K, Oba Y, Nakamura H. (2001) Modification of Arg-13 of mu-conotoxin GIIIA with piperidinyl-Arg analogs and their relation to the inhibition of sodium channels. FEBS Lett 10:503:107-110
    Abstract: mu-Conotoxin GIIIA, a peptide toxin isolated from the marine snail Conus geographus, preferentially blocks skeletal muscle sodium channels in vertebrates. In this study, analogs of mu-conotoxin GIIIA in which essential Arg-13 was replaced with arginine analogs consisting of a piperidyl framework to regulate length and direction of the side chain were synthesized. Synthesized analogs exhibited similar CD and NMR spectra to that of GIIIA, suggesting a three-dimensional structure identical to that of the native toxin. The biological activities of piperidyl analogs were decreased or lost despite the small change in the side chain of Arg-13. The investigated structure-activity relationships in inhibiting electrically stimulated muscle contraction suggest that the guanidinium group at amino acid position 13 interacts best when spaced with three to four carbons and placed in a vertical direction from the peptide loop. Thus, the position of the guanidinium group at Arg-13 of GIIIA must be located in a certain range for its strong interaction with the channel protein.

    Crucial role for N-type Calcium channels in pain perception:
    Hatakeyama S, Wakamori M, Ino M, Miyamoto N, Takahashi E, Yoshinaga T, Sawada K, Imoto K, Tanaka I, Yoshizawa T, Nishizawa Y, Mori Y, Niidome T, Shoji S. (2001) Differential nociceptive responses in mice lacking the alpha(1B) subunit of N-type Ca(2+) channels. Neuroreport 12:2423-2427
    Abstract: The role of N-type Ca(2+) channels in nociceptive transmission was examined in genetically engineered mice lacking the alpha(1B) subunit of N-type channels and in their heterozygote and wild-type littermates. In alpha(1B)-deficient mice, N-type channel activities in dorsal root ganglion neurons and spinal synaptoneurosomes were eliminated without compensation by other types of voltage-dependent Ca(2+) channels. The alpha(1B)-deficient mice showed a diminution in the phase 2 nociceptive responses more extensively than in the phase 1 nociceptive responses of the formalin test. The alpha(1B)-deficient mice exhibited significantly increased thermal nociceptive thresholds in the hot plate test, but failed to increase mechanical nociceptive thresholds in the tail pinch test. These results suggest a crucial role of N-type channels in nociceptive transmission, especially for persistent pain like phase 2 of the formalin test and for nociception induced by thermal stimuli.

    Conantokin Review:
    Castellino, F.J. and Prorok, M. (2000) Conantokins: inhibitors of ion flow through the N-methyl-D-aspartate receptor channels. Curr Drug Targets. 1: 219-235. Review.
    Abstract: Calcium flow through the ion channel of the N-methyl-D-aspartate receptor (NMDAR) has been implicated as contributing to a variety of neuropathologies. This receptor is a complex heteromeric oligomer consisting of different types of subunits, the nature of which governs its properties, as well as its response to a variety of agonists, antagonists, and other types of inhibitors. A new natural series of NMDAR inhibitors, the conantokins, have been shown to be present in the venoms of snails within the genus, Conus. These agents appear to function by inhibition of the spermine/spermidine stimulation of ion flow through the NMDAR channel. These small peptides (17-27 amino acid residues) are highly processed post-translationally. One such processing event is the vitamin K-dependent gamma-carboxylation of glutamate, resulting in placement of gamma-carboxyglutamic acid residues in these peptides. As a result, these peptides then possess the ability to interact with divalent metal ions and concomitantly undergo a conformational alteration. Rational drug design based on the characteristics of these promising peptides requires knowledge of their properties and the manner in which they target the NMDAR. This review summarizes current knowledge in this area.

12 October 2001

3 October 2001

29 September 2001

    VENOM: Striking beauties collection

    The Tennessee Aquarium has mounted a display entitled VENOM: Striking beauties collection. A summary of the creatures and the application of their venom components for beneficial uses is available on the web at Medical Marvel : Venom's Human Side. Included are the Bee, Cameroon red tarantula, Cone shell, Eastern and *Western diamondback rattlesnakes, Giant yellow Israelean scorpion, *Gila monster, Malayan pit viper, Russell's pit viper, Taipan, and the Thailand cobra.

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28 September 2001

    FROM THE ARCHIVE : Two articles about Ziconotide that are still of current interest

    Ziconotide Source on DocMD.com:
    Ziconotide Source - now hosted by DocMD.com - "is an interactive Internet site intended for US audiences. This web site is designed to provide information to physicians and healthcare personnel on important and new aspects of ziconotide, a novel therapeutic modality to treat pain, currently under regulatory review at the US Food and Drug Administration (FDA)". Ziconotide is a synthetic version of conotoxin MVIIA from Conus magus. It has received an "approvable letter" from the FDA for treatment of morphine-resistant neuropathic pain but is yet to receive full approval. This site contains Pain Links, Article Summaries and Clinical Reports about Ziconotide.

    Conquering Pain - new discoveries and treatments offer hope:
    BUSINESS WEEK March 1, 1999: Emily Dickinson tells of the experiences of Laura A. McManus, a 27-year-old from Mount Sinai, N.Y. who is one of the 50 million Americans partly or totally disabled by chronic pain. ''I've been on everything: Darvoset, Percocet, Vicodin, morphine in the pump, Dilaudid in the pump,'' she says. All of these narcotics eventually stopped working, and by 24 she had upped the dosage to the point where she was so drugged she could barely function. ''I was borderline suicidal,'' she says. However, ''One month after being on Ziconotide, it was 'Wow, I was happy,''' she says. In the following months, she started physical therapy, began walking, lost the 70 pounds she gained while the pain was at its worst, returned to college, and danced at a wedding. ''Now,'' she says, ''I can think. I can express my feelings. I can have children, finish school. I can have a life.'' Ziconotide (Neurex / Elan Pharmaceuticals) is but one of a number of new treatments being developed for treatment of chronic pain. Others include the drugs ABT-594 (Abbott Laboratories) ; Actic (Anesta), Celebrex, Vioxx (Monsanto,Merck), Morphidex (Algos Pharmaceutical), Neurontin (Warner-Lambert Co), Prosaptide TX14(a) (Myelos Neurosciences Corp), and opioid-delivering transplants of encapsulated bovine adrenal chromaffin cells (CytoTherapeutics). These are nicely reviewed by Emily Dickinson and Catherine Arnst, with input from Ellen Licking, in New York and Amy Barrett in Philadelphia in this special feature on Conquering Pain in BusinessWeek from 1999 that includes two informative pages : Defining Pain, and Pain Snipers and a downloadable poster in Adobe .pdf format at Pain's pathway and the drugs that block it.

27 September 2001

    Pain Relieving Agents from Cone Shell Toxin":
    Medical pain specialist Hans Georg Kress was interviewed by the Vienna newspaper "Der Standard" about the new pain relieving agent he developed from cone shell toxin. Read an English translation of this interview describing the work he presented at the Vienna pain symposium in 2000.
    Source: Der Standard, Vienna, Austria, September, 27th, 2000.

25 September 2001

17 September 2001

    Cone Shell feature:
    Robert Nordsieck from Austria has constructed a most comprehensive and informative site entitled The Living World of Molluscs intended for "interested users, laymen as well as specialists, with information on the world of molluscs. The text is, as far as possible, written in simple language and thus can be used in school as well as in university, using the pages as complete research media or using single pages". Includes site search engine, images, movie clips, and a forum. The site is available in German and English. It includes a section on Cone Shells.

11 September 2001

9 September 2001

    Novel cone shell venom components target adrenoceptors and noradrenaline transporters:
    The venom of cone snails contains peptides that target mammalian receptors, often quite selectively. Now, researchers from the University of Queensland and Xenome Ltd. have discovered two new classes of conopeptides, one that targets alpha-1-adrenoceptors, and another that targets the neuronal noradrenaline transporter. Both types of inhibitor are selective to the receptors, acting as reversible noncompetitive inhibitors. Both could provide alternative avenues for the identification of inhibitor drugs.

    Sharpe, I.A., Gehrmann, J., Loughnan, M.L., Thomas, L., Adams, D.A., Atkins, A., Palant, E., Craik, D.J., Adams, D.J., Alewood, P.F. and Lewis, R.J. (2001) "Two new classes of conopeptides inhibit the alpha-1-adrenoceptor and noradrenaline transporter". Nature Neurosci. 4: 902-907.
    Abstract:Cone snails use venom containing a cocktail of peptides ('conopeptides') to capture their prey. Many of these peptides also target mammalian receptors, often with exquisite selectivity. Here we report the discovery of two new classes of conopeptides. One class targets alpha 1-adrenoceptors (rho-TIA from the fish-hunting Conus tulipa), and the second class targets the neuronal noradrenaline transporter (chi-MrIA and chi-MrIB from the mollusk-hunting C. marmoreus). rho-TIA and chi-MrIA selectively modulate these important membrane-bound proteins. Both peptides act as reversible non-competitive inhibitors and provide alternative avenues for the identification of inhibitor drugs.

8 September 2001

4 September 2001

    Listing in AnimalFocus:
    AnimalFocus is a multilingual extensive free listing of quality links to information about animals. Animals are main grouped by usage as pet, as food (farming), for show (zoo), as professional, and finally, in the wild.
    The present "Cone Shells and Conotoxins" homepage is listed under the Category : In the Wild: Water : Animals : Molluscs. Enter Cone shells in the Search box below.
    Animal Focus, all about animals as pets, in farming, in zoos and aquariums, working, and in the wild AnimalFocus.com

3 September 2001

    More Cone Shells in Art:
    Thanks to Marco Bettocchi and Giancarlo Paginelli who responded on CONCH-L mailing list confirming my identification of the cones in the Balthasar's paintings at the Rijksmuseum web site (see entry below for 29 August), and for pointing out that visible in the larger image of the painting with the Conus striatus there is another cone that appears to be a Conus capitaneus (the orange one). Note also that the logo of Giancarlo Paginelli's "Cone Shells" web site is drawn from the darker Rembrandt's engraving, but reversed. Alfonso Pina also responded informing me that he has a malacological art section right on his own web site, and which includes many Dutch masters. Look at http://www.eumed.net/malakos/arte2 . For example, he has there a painting in private collection in New York by Balthasar van der AST entitled Ramo de Flores (1630) that includes a Conus chaldeus and Conus textile; another Flores en jarrón con conchas e insectos,1628-30, entrusted to the National Gallery, London depicting a Conus striatus and a Conus marmoreus, another Bodegón, (1620) with a Conus pennaceus ? and Bodegón (1628), with Conus striatus and marmoreus and a third unidentified cone.

31 August 2001

    Glory-of-the-Atlantic Cone:
    Karen VanderVen, Contributing Editor of Jacksonville Shell Club, recently accompanied Peggy Williams on a trip to Belize. Not only did Karen get common species, including Conus jaspideus Gmelin, 1791 [Jasper Cone], which might be expected, but came back with a Conus granulatus Linnaeus, 1758 [Glory-of-the-Atlantic Cone] (a generous gift from the Dive Shop). You can read Karen's well written, illustrated account of the trip "From The Lamanai Ruins To The San Pedro Lagoon - Ooh, La, La! Shelling In The Belize Experience (September-October, 2001) "at: www.jaxshells.org/belize.htm & jaxshells.org/belize1.htm. While at the Jacksonville Shell Club site, you may be interested to view a collection of other Selected Western Atlantic Conidae and read Selected Past Newsletter Articles including one by Norma Carlson "Now there are two" (July-August 2001) describing the find of a second sinistral Conus floridanus Gabb, 1868 [Florida Cone] (now known as Conus anabathrum Crosse, 1865).

29 August 2001

    Conus at Rijksmuseum, Amsterdam:
    Rembrant owned an extensive collection of art and curiosities which he employed in his compositions. But only once did he make an etching based on an object in his collection. The two prints of the etching of a cone shell shown here are his only still-life prints. The subject of the picture is a marbled cone shell - 'conus marmoreus', also [darker print]- which is found in the Indian Ocean. Rembrandt selected the most interesting angle for the depiction: showing both the spiral at the top and the opening at the side. But he paid little heed to the laws of nature. Because of the print process, the impression in the picture is back to front: the whorl of the shell is anti-clockwise (sinistral instead of dextral). This rarely occurs in real life and has not been reported for Conus marmoreus. On the other hand, Rembrandt remembered to sign and date the work in mirror-image on the plate. (Click on zoom for a larger image that you can move around with your mouse; or look at the Enlarged Image of Conus marmoreus.

    Exotic shells were a favourite item in still life paintings, often in combination with large bouquets of flowers, as in the two floral still life paintings depicting a Conus striatus and Conus capitaneus and a Conus pennaceus by Balthasar van der Ast. [Look at base of vase for the shells, one of which appears to be a Conus striatus with a Conus capitaneus behind ; and in the other a Conus pennaceus. Zoom and scroll image up or look at the Enlarged image containing Conus striatus & capitaneus and Conus pennaceus]

28 August 2001

    w-Conotoxin MVIIA and neuroprotection after ischemia:
    In this study, 'Toto' Olivera and colleagues (Aryan Azimi-Zonooz, Chad B. Kawa and Cheryl D. Dowell) used radiolabeled omega-conotoxin MVIIA (w-MVIIA)on thin sections of gerbil hippocampus, to provide a more detailed localization of N-type Voltage Gated Calcium Channels (VGCCs) than previously reported. In contrast to findings in the rat, the investigators did not observe any demonstrable neuroprotection by w-MVIIA in the gerbil model of cerebral ischemia. This raises the possibility that efficacy of w-MVIIA in rat may be secondary to a decrease in post-ischemic brain temperature. Of value, [125I]w-GVIA can be used as another synaptic marker to assess post-ischemic synaptic changes and organization.
    Azimi-Zonooz, A., Kawa, C.B., Dowell, C.D. & Olivera, B.M. (2001) "Autoradiographic localization of N-type VGCCs in gerbil hippocampus and failure of w-conotoxin MVIIA to attenuate neuronal injury after transient cerebral ischemia". Brain Research, 907:61-70
    Abstract:In the mammalian central nervous system, transient global ischemia of specific duration causes selective degeneration of CA1 pyramidal neurons in hippocampus. Many of the ischemia-induced pathophysiologic cascades that destroy the neurons are triggered by pre- and postsynaptic calcium entry. Consistent with this, many calcium channel blockers have been shown to be neuroprotective in global models of ischemia. w-Conotoxin MVIIA, a selective N-type VGCC blocker isolated from the venom of Conus magus, protects CA1 neurons in the rat model of global ischemia, albeit transiently. The mechanism by which this peptide renders neuroprotection is unknown. We performed high-resolution receptor autoradiography with the radiolabeled peptide and observed highest binding in stratum lucidum of CA3 subfield, known to contain inhibitory neurons potentially important in the pathogenesis of delayed neuronal death. This finding suggested that the survival of stratum lucidum inhibitory neurons might be the primary event, leading to CA1 neuroprotection after ischemia. Testing of this hypothesis required the reproduction of its neuroprotective effects in the gerbil model of global ischemia. Surprisingly, we found that w-MVIIA did not attenuate CA1 hippocampal injury after 5 min of cerebral ischemia in gerbil. Possible reasons are discussed. Lastly, we show that the peptide can be used as a synaptic marker in assessing short and long-term changes that occur in hippocampus after ischemic injury.

24 August 2001

    Conus magus envenomates a fish:
    Photo of Conus magus snail attacking a small fish. After spearing its victim, the snail releases the venom. Toxic components of the venom inhibit neural transmission. One of the venom components isolated by researchers, the peptide omega-conotoxin MVIIA, was found to be an N-type calcium channel antagonist that plays an important role in inhibition of nociception. It was first called SNX-111 (Neurex Corp) and has been developed into the drug Ziconotide (Elan) for the treatment of morphine-resistant neuropathic pain. Source: Article by Peter S. Staats, MD and Veronica Mitchell, MD on "Future Directions for Intrathecal Therapies". For an associated article regarding the pending advances in intrathecal drug therapy for chronic pain, see "Intrathecal Drug Therapy for Chronic Pain: From Basic Science to Clinical Practice" by Patrick M. Dougherty, Ph.D., and Peter S. Staats, M.D., as it appears in Anesthesiology 1999; 91(6):1891-1918

23 August 2001

    Omega-Conotoxin MVIIA binding to N-type calium channels:
    T. Luchian from the Faculty of Physics, Department of Biophysics and Medical Physics, 'Alexandru I. Cuza' University, Blvd. Carol I No. 11, R-6600, Iasi, Romania. [luchian@uaic.ro ] has examined the effect of the beta3 subunit on omega conotoxin MVIIA (also known as SNX-111, Ziconotide) binding to the neuronal N-type calcium channels expressed in Xenopus laevis oocytes.
    Luchian, T. (2001) The influence exerted by the beta(3) subunit on MVIIA omega-conotoxin binding to neuronal N-type calcium channels.Biochim Biophys Acta. 1512: 329-334.
    Abstract: In the present study, two-electrode voltage-clamp techniques have been used to assess the interaction between the MVIIA omega-conotoxin and an isoform of the N-type Ca(2+) channel alpha subunit (alpha(1B-d)). Cloned alpha(1B-d) Ca(2+) channels were expressed in Xenopus laevis oocytes in the presence and absence of the beta(3) subunit. Coexpression of the beta(3) subunit significantly shifted the IC(50) value for MVIIA inhibition of central N-type Ca(2+) channel current. Analysis of the peak conductance vs. depolarising voltage dependence suggested that the beta(3) subunit has no apparent effect on the gating charge which accompanies the closed-open transition of the channels. Instead, coexpression of the beta(3) subunit led to an approx. 10 mV shift to more hyperpolarised potentials in the voltage-dependent activation of N-type Ca(2+) channels. We conclude that MVIIA alters the surface charge on the N-type Ca(2+) channels and might induce allosteric changes on the structure of the channel, leading to an increase in the dissociation constant of MVIIA binding.

    Interstitial Cystitis and Pain:
    The Interstitial Cystitis Association has an excellent and informative web site that contains information about new medications including Ziconotide (SNX-111) from the cone snail Conus magus for the treatment of pain associated with Interstitial Cystitis (IC). Take a read of IC and Pain, by Lucrecia Perilli, Part 2 of a 4-part series. (see also Part I; Part III; and Part IV.

20 August 2001