Cone snails produce this unique class of toxins to kill their prey. Conotoxins have been the focus of intense pharmacological studies partially due to the unusual and potentially useful effects that they have on some organisms.
Composition
It is a short, highly post-translationally modified peptides. The post-translational modifications occur in steps to arm the venom before use. Disulfide bridges between cysteine resins abound.
Stiff Tails
Conus radiatus produces a venom called Contryphan that when injected into baby mice, puts them to sleep. When injected into adult mice, it causes their tails to become stiff. The ability of this toxin to make the tails of adult mice stiff is used as an assay.
The King Kong Effect
The worm hunting Mediterranean cone snail, Conus ventricosus produces this toxin. When purified and put into a lobster tank, it will make the lobster press itself up against the glass and beat its pinchers against its chest like King Kong.
Applications in Medicine
In humans, these chemicals may be used as drugs that affect the receptor sites of neurons.
Small-molecule drugs like these are becoming very popular. Among other things, it may be used to treat pain, mental disorders, and a variety of neurological problems. They may also be used as blood thinners and blood clotting agents.
Web References
http://www.science.fau.edu/chemistry/mari/usscono.html
http://grimwade.biochem.unimelb.edu.au/cone/ConeReview2002.html