Attachment of rattlesnake venom myotoxin a to sarcoplasmic reticulum: peroxidase conjugated method.

Myotoxin a is a muscle-damaging toxin isolated from the venom of Crotalus atrox (western diamondback rattlesnake) and is composed of 42 amino acid residues. Earlier electron microscopic observation indicated that the toxin causes extensive swelling of the sarcoplasmic reticulum followed by disorganization of the sarcomers. In the present paper we describe the evidence for the attachment of peroxidase-conjugated myotoxin a to the membrane of sarcoplasmic reticulum of human muscle. It is thus suggested that the attachment of the toxin to the sarcoplasmic reticulum and the subsequent swelling are the first steps in myonecrosis induced by myotoxin a.