One of the toxic principles isolated from rattlesnake venom: Slotta, Fraenkel-Conrat, Ber. 71, 1076 (1938). A polypeptide complex of probably two components, one acidic and one basic, having mol wts of ≈9000 and 12,000 resp. The subunits do not retain the toxicity of crotoxin but show synergistic action in combination: Hendon, Fraenkel-Conrat, Proc. Natl. Acad. Sci. USA 68, 1560 (1971). Amino acid analyses and fractionation studies: Fraenkel-Conrat, Singer, Arch. Biochem. Biophys. 60, 64 (1956); Rübsamen et al., Arch. Pharmacol. 270, 274 (1971); Horst et al., Biochem. Biophys. Res. Commun. 46, 1042 (1972). Review of early chemical studies: Fraenkel-Conrat, Singer, Publ. Am. Assoc. Advan. Sci. 44, 259 (1956). Monograph: Behringwerk-Mitteilungen Sonderband, Die Giftschlangen der Erde (N. G. Elwert, Marburg, 1963) 464 pp. Pharmacology: Brazil, Excell, J. Physiol. (London) 212, 34P (1970); Brazil et al., ibid. 234, 63P (1973); Habermann et al., Arch. Pharmacol. 273, 313 (1972). See also Crotamine.