Chemical Properties and Physiological Activity of a Neuroactive Component from the Venom of Conus Californicus

Citation

Elliott, Ellen Jeanne (1975) Chemical Properties and Physiological Activity of a Neuroactive Component from the Venom of Conus Californicus. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/6kgj-m088. https://resolver.caltech.edu/CaltechTHESIS:03022022-182739139

Abstract

A small molecular weight component, named conusine, was purified from the venom of the marine snail Conus californicus. The solubility properties, enzyme susceptibilities, heat and pH sensitivity, spectral characteristics and reactivity with various indicator reagents of conusine were determined. Conusine was found to inhibit the excised, spontaneously beating heart of the clam Mercenaria mercenaria. This inhibition was blocked by those antagonists which were found to block acetylcholine inhibition of the heart. In addition, in the medial cells of the Aplysia pleural ganglion iontophoretically applied conusine was found to activate selectively a cholinergic receptor which mediates a slow hyperpolarization of the cell due to an increase in K⁺ permeability. Conusine was concluded to be a cholinergic agonist specific for this type of slow hyperpolarizing receptor. From additional pharmacological studies of various cholinergic agonists and antagonists on the clam heart, this tissue was hypothesized to contain the same type of slow hyperpolarizing cholinergic receptor as the medial cells of the Aplysia pleural ganglion.

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