Rapid mass spectral identification of contryphans. Detection of characteristic peptide ions by fragmentation of intact disulfide-bonded peptides in crude venom

Thakur, Suman S and Balaram, Padmanabhan (2007) Rapid mass spectral identification of contryphans. Detection of characteristic peptide ions by fragmentation of intact disulfide-bonded peptides in crude venom. In: Rapid Communications in Mass Spectrometry, 21 (21). pp. 3420-3426.

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Abstract

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 $C^\alpha H$ or $C^\beta H$ proton, resulting in distinct product ions, with the subsequent loss of elemental sulfur, $H_2S$ or $H_2S_2$. 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.

Item Type:	Journal Article
Publication:	Rapid Communications in Mass Spectrometry
Publisher:	John Wiley & Sons
Additional Information:	Copyright of this article belongs to John Wiley & Sons
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	18 Dec 2008 07:12
Last Modified:	19 Sep 2010 04:52
URI:	http://eprints.iisc.ac.in/id/eprint/16556

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