Premium
Rapid mass spectral identification of contryphans. Detection of characteristic peptide ions by fragmentation of intact disulfide‐bonded peptides in crude venom
Author(s) -
Thakur Suman S.,
Balaram Padmanabhan
Publication year - 2007
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3225
Subject(s) - chemistry , conus , cleavage (geology) , fragmentation (computing) , tandem mass spectrometry , conotoxin , disulfide bond , peptide , venom , ion , mass spectrometry , stereochemistry , chromatography , crystallography , biochemistry , organic chemistry , medicine , geotechnical engineering , fracture (geology) , computer science , engineering , anatomy , operating system
The mass spectrometric cleavage of intact disulfide‐bonded peptides in conus venom has been investigated. Contryphans containing a single disulfide bond are shown to fragment preferentially at X–Pro bonds, giving rise to linearized, unsymmetrical cystine peptides, which subsequently fragment by multiple pathways at the disulfide bridge. Cleavage at the disulfide bond can be initiated by initial loss of the C α H or C β H proton, resulting in distinct product ions, with the subsequent loss of elemental sulfur, H 2 S or H 2 S 2 . Contryphans from Conus amadis, Conus loroisii , and Conus striatus are presented as examples, in which detailed assignment of the product ions resulting from tandem mass spectrometric analysis of the intact disulfide is also accomplished. Characteristic fragments arising from conserved contryphan sequences can be used as diagnostic, permitting rapid identification of this class of peptides in crude venom. The observed fragment ions obtained for contryphans in diverse cone snail species are also compared. Copyright © 2007 John Wiley & Sons, Ltd.