Isolation of a myotoxin from the venom of Agkistrodon contortrix laticinctus (broad-banded copperhead) and pathogenesis of myonecrosis induced by it in mice

Abstract

E. K. Johnson and C. L. Ownby. Isolation of a myotoxin from the venom of Agkistrodon contortrix laticinctus (broad-banded copperhead) and pathogenesis of myonecrosis induced by it in mice. Toxicon 31, 243–255, 1993.—A myotoxin was isolated from the venom of the broad-banded copperhead ( Agkistrodon contortrix laticinctus) by HPLC using anion and cation exchange chromatography. The toxin has a mol. wt of approximately 14,000 and has a p I greater than 9. It does not have phospholipase A activity, but does induce myonecrosis of skeletal muscle cells characterized by a hypercontraction of myofilaments. Electron microscopic analysis showed that the myotoxin appears to disrupt the sarcolemma of skeletal muscle cells. ACL myotoxin is very similar in mol. wt, amino acid composition, and myotoxic activity to myotoxins isolated from the venoms of Bothrops asper and Bothrops nummifer from Central America, suggesting that homologs of this toxin may be found in other crotaline snake venoms.