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 highly venomous caenophidian snakes (also referred to as "colubroidian snakes"), thus suggesting that most venom evolution took place after this lineage diverged from other snakes. The primary mechanism for the diversification of venom is thought to be the duplication of gene coding for other tissues, followed by their expression in the venom glands. The proteins then evolved into various venom proteins through natural selection. This process, known as the birth-and-death model, is responsible for several of the protein recruitment events in snake venom. These duplications occurred in a variety of tissue types with a number of ancestral functions. Notable examples