The molecular weight of crotoxin

Abstract

Crotoxin, the crystalline poison from the rattlesnake (Crotalus terrificus), was investigated for its molecular wt. by ultracentrifugal methods. Sedimentation velocity and diffusion measurements gave S20 = 3.13, D20 = 8.59, and Mwt. = 30,000. Sedimentation equilibrium measurements gave Mwt. = 30,500. The molecule is split into smaller, inactive substances by treatment with cysteine or by warming in alkaline soln.