Apamin therapeutic effect on Parkinson's disease. Dopamine, which is depleted in this disease, will be released from midbrain dopaminergic neurons when these SK channels are inhibited. SK channels have also been proposed as targets for the treatment of epilepsy, emotional disorders and schizophrenia. 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
Evolution of snake venom degree of resistance to the venom of rattlesnakes, suggesting that the rats have evolved in response to the snake venom, thus renewing selection pressure upon the snakes. The selection pressure on snake venom is thought to be selecting for functional diversity within the proteins in venom, both within a given species, and across species. The genes that code for venom proteins in some snake genera have a proportion of synonymous mutations that is lower than would be expected if venom were evolving through neutral evolutionary processes. In addition, snake venom is metabolically costly for a snake to produce, which scientists