The toxicity of some precipitated fractions of dried moccasin venom (Ancistrodon piscivorus piscivorus).

Abstract

Summary and Conclusions 1. Whole dried venom of the cottonmouth moccasin, Ancistrodon piscivorus piscivorus, was separated into eight fractions by precipitation with saturated (NH4)2SO4 at concentrations of 45%, 52%, 62%, and 75%. No protein was precipitable at concentrations beyond 75%. Four of these fractions consisted of the protein material primarily precipitated at each salt concentration, and four of minute amounts of material associated with each of the former but insoluble and separable by centrifugation after dialysis. These latter correspond to globulin precipitates said to occur under these conditions in the venom of the Brazilian rattlesnake, Crotalus terrificus terrificus. 2. Toxicity, hemolytic activity, and ultraviolet absorption spectra were determined for the four primary protein fractions (1, 2, 3, 4), but only hemolytic activity for the four globulin fractions (1G, 2G, 3G, 4G) was determined. All of the former four protein fractions were found to be toxic, varying only slightly in degree of toxicity. The syndrome following the injection of a lethal dose in the mouse has been described. 3. The hemolytic activity of these fractions was found to be minimal and associated primarily with only fraction 2. Some hemolytic activity was also observable in association with two globulin fractions. 4. The ultraviolet absorption spectra of the four primary fractions were very similar, showing a maximum at 280 mµ characteristic of proteins rich in aromatic amino acids. Fraction 4 (75%) showed considerably more absorption from 235–290 mµ than did fractions 1, 2, and 3 at the same concentrations. 5. It has been concluded that the toxic principles precipitated by these methods from moccasin venom are different from those derived from the venom of Crotalus durissus terrificus.