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Sea anemones produce many different neurotoxins with related structure and function. Proteins belonging to this family include the neurotoxins, of which there are several, including calitoxin and anthopleurin. The neurotoxins bind specifically to the sodium channel, thereby delaying its inactivation during signal transduction, resulting in strong stimulation of mammalian cardiac muscle contraction. Calitoxin 1 has been found in neuromuscular preparations of crustaceans, where it increases transmitter release, causing firing of the axons. Three disulphide bonds are present in this protein.
References
Norton TR (1981). "Cardiotonic polypeptides from Anthopleura xanthogrammica (Brandt) and A. elegantissima (Brandt)". Fed. Proc. 40 (1): -. PMID6108877.
Yasunobu KT, Norton TR, Reimer NS, Yasunobu CL (1985). "Amino acid sequence of the Anthopleura xanthogrammica heart stimulant, anthopleurin-B". J. Biol. Chem. 260 (15): -. PMID4019448.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Scanlon MJ, Pallaghy PK, Norton RS, Monks SA (1995). "Solution structure of the cardiostimulant polypeptide anthopleurin-B and comparison with anthopleurin-A". Structure. 3 (8): -. PMID7582896.{{cite journal}}: CS1 maint: multiple names: authors list (link)