Characterization of the neurotoxic constituents of Conus geographus (L) venom

摘要: Abstract The crude venom of the marine gastropod Conus geographus (L) has been separated into three lethal constituents and their actions at mammalian neuromuscular junction examined. Chromatography Sephadex G-50 gave one toxic fraction, which was resolved by ion exchange chromatography on SP-Sephadex components. These components were individually purified diafiltration G-15 to give Toxins I,II III. I II in concentrations greater than 5 ug/ml reduced amplitude end-plate potentials miniature potentials; Toxin also blocked depolarization muscle fibres produced carbachol; neither toxin affected generation action fibres. III rapidly reversibly fibres; it had no effect resting membrane potential nor epps or mepps. It slowly compound recorded from isolated sciatic nerves but this not reversible experiments. rate increased stimulation preparation. is suggested that acts blocking inward movement sodium during activity. appeared be a nonadeca eicosa peptide possibly having cystine residue N-terminal position.