Structures of several conotoxins which have been used as research tools for studying ion channel function. Click on each image to access a molecular model of the conotoxin derived from its empirically derived 3D structure. To manipulate these images you must have Chime or RasMol. Chime is a Netscape and Internet Explorer 4 browser plugin which allows you to view 3D structures online. The rendered image can be rotated and viewed in any format (wire-frame, ball-and-stick, space filling) and particular features displayed (eg. disulfide bonds, hydrogen bonds , etc). If you have not already done so, download Chime plugin from MDL, (or download RasMol as a stand-alone program).


alpha-conotoxin Alpha-conotoxin PnIa: This is a selective blocker of the neuronal-type nicotinic receptor, a member of the ligand-gated ion channel family. It is from the cone snail Conus pennaceus.

Reference: Hu SH, Gehrmann J, Guddat LW, Alewood PF, Craik DJ, Martin JL (1996) The 1.1 A crystal structure of the neuronal acetylcholine receptor antagonist, alpha-conotoxin PnIA from Conus pennaceus. Structure. 4: 417-423.

To link to original references documenting the determination of the 3D structure of alpha-conotoxin PnIa (PDB Id: 1PEN) click here


Omega-conotoxin MVIIa (SNX-111) Omega-conotoxin MVIIa (SNX-111, Ziconotide): This is a selective blocker for N-type calcium channels. It is from the cone snail Conus magus and contains a short triple stranded antiparallel beta sheet.

Reference: Kohno, T, Kim, J.I., Kobayashi, K., Kodera, Y., Maeda, T. and Sato, K. (1995) Three-dimensional structure in solution of the calcium channel blocker omega-conotoxin MVIIA. Biochemistry. 34: 10256-10265.

To link to the original references documenting the determination of the 3D structure (PDB Id: 1OMG) click here.


Omega-conotoxin MVIIc Omega-conotoxin MVIIc: This is a selective blocker for P-type calcium channels. It is from the cone snail Conus magus.

Reference: Farr-Jones S, Miljanich G.P., Nadasdi L., Ramachandran J, and Basus V.J. (1995) Solution structure of omega-conotoxin MVIIC, a high affinity ligand of P-type calcium channels, using 1H NMR spectroscopy and complete relaxation matrix analysis. J Mol Biol. 248: 106-124.

To link to the original references documenting the determination of the 3D structure (PDB Id: 1OMN) click here.


mu-conotoxin mu-conotoxin Giiib: This cone snail derived toxin (from Conus geographus) is a specific blocker of skeletal sodium channels. Its folding is similar to scorpion toxins and insect defensins. Its structure is stabilized by 3 disulfide bonds.

Reference: Hill, J.M., Alewood,P.F. and CraikD.J. (1986) Three-dimensional solution structure of mu-conotoxin GIIIB, a specific blocker of skeletal muscle sodium channels. Biochemistry 3: 8824-8835.

To link to original references documenting the determination of mu-conotoxin's 3D structure (PDB Id: 1GIB) click here.

For structures of OTHER CONOTOXINS, see list updated 26/12/'98 Conotoxin Structures in the Protein Data Base

For structures of OTHER ION CHANNEL TOXINS, see J.Christian Hesketh's Ion Channels and Toxins HomePage.


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