Mass spectral identification of Vc1.1 and differential distribution of conopeptides in the venom duct of conus victoriae. effect of post-translational modifications and disulfide isomerisation on bioactivity

Abstract

Molluscs of the genus Conus (cone shells) are carnivorous, feeding on marine worms, small fish and other marine molluscs. They capture their prey by injecting venom containing hundreds of neurally active peptide components. These peptides are classed as conotoxins and consist of small disulfide-bonded peptides exhibiting a high degree of post-translational modifications (PTMs). The functional roles of these modifications remain largely unknown. Two of the most frequently observed modifications are γ-carboxylation of glutamate and hydroxylation of proline (Buczek et al. Cell Mol Life Sci 62:3067, 2005). Vc1.1 is an α-conotoxin from Conus victoriae (Sandall et al. Biochemistry 42(22):6904-6911..