Apamin Apamin Apamin is an 18 amino acid peptide neurotoxin found in apitoxin (bee venom). Dry bee venom consists of 2–3% of apamin. Apamin selectively blocks SK channels, a type of Ca-activated K channel expressed in the central nervous system. Toxicity is caused by only a few amino acids, these are cysteine, lysine, arginine, arginine and histidine. These amino acids are involved in the binding of apamin to the Ca-activated K channel. Due to its specificity for SK channels, apamin is used as a drug in biomedical research to study the electrical properties of SK channels and their role in the
Evolution of snake venom splicing. The Elapid snake "Bungarus fasciatus", for example, possesses a gene that is alternatively spliced to yield both a venom component and a physiological protein. Further diversification may have occurred by gene loss of specific venom components. For instance, the rattlesnake ancestor is believed to have had genes for neurotoxic PLA2 toxins, which are absent in modern non-neurotoxic "Crotalus" species. The various recruitment events had resulted in snake venom evolving into a very complex mixture of proteins. The venom of rattlesnakes, for example, includes nearly 40 different proteins from different protein families, and other snake venoms have been found to