This venom insulin, from a fish-hunting cone snail, facilitates prey capture by rapidly inducing hypoglycemic shock (PubMed:25605914, PubMed:27617429). It is one of the smallest known insulin found in nature and lacks the C-terminal segment of the B chain that, in human insulin, mediates engagement of the insulin receptor and assembly of the hormone's hexameric storage form (PubMed:27617429). Despite lacking this segment, it both binds and activates human insulin receptor (long isoform (HIR-B)) with a high potency (EC(50)=16.28 nM) (PubMed:30747102, PubMed:27617429). In vivo, intraperitoneal injection of this peptide into zebrafish lowers blood glucose with the same potency than human insulin (PubMed:25605914, PubMed:30747102). In addition, when applied to water, this peptide reduces overall locomotor activity of zebrafish larvae, observed as a significant decrease in the percentage of time spent swimming and movement frequency (PubMed:25605914). When tested on a mouse model of diabetes, this insulin also lowers blood glucose with a 10-fold lower potency than human insulin (PubMed:30747102). Heterodimer of A and B chains; disulfide-linked. Expressed by the venom gland. with 1 hydroxyPro (residue 34) and with 3 carboxyglutamate (residues 41, 98 and 109). The measured ranges are 30-52, 95-114. with 2 hydroxyPro (residues 34 and 104) and with 3 carboxyglutamate (residues 41, 98 and 109). The measured ranges are 30-52, 95-114. without hydroxyPro and with 3 carboxyglutamate (residues 41, 98 and 109). The measured ranges are 30-52, 95-114. Venom insulins constitute about 1/25 of the total venom of C.geographus. Belongs to the insulin family. Sweet poison - Issue 191 of May 2017