Alpha-Conotoxin GIA

**Semantic type:** Hazardous or Poisonous Substance

**Definition:** A 15-amino acid alpha-conotoxin isolated from the venom of the cone snail Conus geographus that is a competitive antagonist of the muscle-type nicotinic acetylcholine receptors, blocking synaptic transmission at the neuromuscular junction. Alpha-conotoxins are identified by a characteristic arrangement of four-cysteine residues (-CC-C-C-) and disulfide bonding of Cys1-Cys3 and Cys2-Cys4. Alpha-conotoxin GIA is identical in sequence to the neurotoxin alpha-conotoxin GI except for the presence of additional residues of glycine and lysine at the carboxyl terminus.

**Synonyms:** - ALPHA-CONOTOXIN GIA - Alpha-GIA - Alpha-GIA