Purification and biochemical study of viriditoxin, tissue damaging toxin, from prairie rattlesnake venom

Abstract

Rattlesnake poisoning frequently produces a severe tissue damaging effect including myonecrosis and hemorrhage. Viriditoxin was isolated from the venom of the prairie rattlesnake (C. viridis viridis) and its chemical properties and biological activities associated with tissue damage were investigated. The toxin had a MW of 115,000 with an isoelectric point of 4.8. Amino acid composition analyses indicated that the toxin consisted of 1018 residues with high content of acidic amino acid residues. Circular dichroism [CD] was used to examine conformation of viriditoxin. Although there was some indication of a high .beta.-sheet content, it was not possible to identify the exact conformation due to anomalous CD spectra. Viriditoxin had myotoxic and hemorrhagic activities. High serum creatine kinase activity of mice injected with the toxin substantiated the destructive action of viriditoxin on muscle. Viriditoxin had an LD50 value of 5.0 .mu.g/g in mice indicating the protein was moderately lethal in addition to its tissue damaging effect.