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Isolation and characterisation of conomap‐Vt, a d ‐amino acid containing excitatory peptide from the venom of a vermivorous cone snail
Author(s) -
Dutertre Sébastien,
Lumsden Natalie G.,
Alewood Paul F.,
Lewis Richard J.
Publication year - 2006
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2006.06.011
Subject(s) - venom , conus , conotoxin , snail , peptide , homology (biology) , neurotransmission , biology , amino acid , cholinergic , chemistry , biochemistry , muscarinic acetylcholine receptor , biophysics , anatomy , neuroscience , receptor , ecology
Cone snail venom is a rich source of bioactives, in particular small disulfide rich peptides that disrupt synaptic transmission. Here, we report the discovery of conomap‐Vt (Conp‐Vt), an unusual linear tetradecapeptide isolated from Conus vitulinus venom. The sequence displays no homology to known conopeptides, but displays significant homology to peptides of the MATP (myoactive tetradecapeptide) family, which are important endogenous neuromodulators in molluscs, annelids and insects. Conp‐Vt showed potent excitatory activity in several snail isolated tissue preparations. Similar to ACh, repeated doses of Conp‐Vt were tachyphylactic. Since nicotinic and muscarinic antagonists failed to block its effect and Conp‐Vt desensitised tissue remained responsive to ACh, it appears that Conp‐Vt contractions were non‐cholinergic in origin. Finally, biochemical studies revealed that Conp‐Vt is the first member of the MATP family with a d ‐amino acid. Interestingly, the isomerization of l ‐Phe to d ‐Phe enhanced biological activity, suggesting that this post‐translational modified conopeptide may have evolved for prey capture.