Determining sequences and post‐translational modifications of novel conotoxins in Conus victoriae using cDNA sequencing and mass spectrometry

• DOI: 10.1002/jms.624
• Publication Date: 2004-05-18T18:00:38Z
• Authors: Jennifer A. Jakub...; David A. Keays; Wayne P. Kelley; David W. Sandall; Jon‐Paul Bingham; Bruce G. Livett; Ken R. Gayler; Jonathan V. Sweedler
• Keywords: Conotoxin; Conus; Bottom-up proteomics; Residue (chemistry)

Abstract A combination of cDNA cloning and detailed mass spectrometric analyses was employed to identify novel conotoxins from Conus victoriae . Eleven conotoxin sequences were determined using molecular methods: one belonging the superfamily (Vc1.1), six O (Vc6.1–Vc6.6) four members T (Vc5.1–Vc5.4). In order verify post‐translational modifications (excluding disulfide connectivity) three conotoxins, vc1a, vc5a vc6a, deduced Vc1.1, Vc5.1, Vc6.1, respectively, liquid chromatography/electrospray ionization ion trap spectrometry, matrix‐assisted laser desorption/ionization time‐of‐flight spectrometry nanospray with collisionally induced dissociation performed on reduced alkylated venom fractions. We report that native form α‐conotoxin Vc1.1 (an unmodified 16 amino acid residue peptide has notable pain‐relieving capabilities), includes a hydroxyproline γ‐carboxyglutamate residue. Conotoxin is 10‐residue two bonds vc6a 25 bonds. Copyright © 2004 John Wiley & Sons, Ltd.