Electron transfer dissociation of synthetic and natural peptides containing lanthionine/methyllanthionine bridges

Dolle, Ashwini B and Jagadeesh, Narasimhappagari and Bhaumik, Suman and Prakash, Sunita and Biswal, Himansu S and Gowd, Konkallu Hanumae (2018) Electron transfer dissociation of synthetic and natural peptides containing lanthionine/methyllanthionine bridges. In: RAPID COMMUNICATIONS IN MASS SPECTROMETRY, 32 (11). pp. 831-843.

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Abstract

RationaleThe modes of cleavage of lanthionine/methyllanthionine bridges under electron transfer dissociation (ETD) were investigated using synthetic and natural lantipeptides. Knowledge of the mass spectrometric fragmentation of lanthionine/methyllanthionine bridges may assist in the development of analytical methods for the rapid discovery of new lantibiotics. The present study strengthens the advantage of ETD in the characterization of posttranslational modifications of peptides and proteins. MethodsSynthetic and natural lantipeptides were obtained by desulfurization of peptide disulfides and cyanogen bromide digestion of the lantibiotic nisin, respectively. These peptides were subjected to electrospray ionization collision-induced dissociation tandem mass spectrometry (CID-MS/MS) and ETD-MS/MS using an HCT ultra ETDII ion trap mass spectrometer. MS3 CID was performed on the desired product ions to prove cleavage of the lanthionine/methyllanthionine bridge during ETD-MS/MS. ResultsETD has advantages over CID in the cleavage of the side chain of lanthionine/methyllanthionine bridges. The cleavage of the N-C backbone peptide bond followed by C-terminal side chain of the lanthionine bridge results in formation of c(center dot+) and z(+) ions. Cleavage at the preceding peptide bond to the C-terminal side chain of lanthionine/methyllanthionine bridges yields specific fragments with the cysteine/methylcysteine thiyl radical and dehydroalanine. ConclusionsETD successfully cleaves the lanthionine/methyllanthionine bridges of synthetic and natural lantipeptides. Diagnostic fragment ions of ETD cleavage of lanthionine/methyllanthionine bridges are the N-terminal cysteine/methylcysteine thiyl radical and C-terminal dehydroalanine. Detection of the cysteine/methylcysteine thiyl radical and dehydroalanine in combined ETD-CID-MS may be used for the rapid identification of lantipeptide natural products.

Item Type:	Journal Article
Publication:	RAPID COMMUNICATIONS IN MASS SPECTROMETRY
Publisher:	WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ USA
Additional Information:	Copy right for this article belong to WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ USA
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	05 Jun 2018 14:08
Last Modified:	05 Jun 2018 14:08
URI:	http://eprints.iisc.ac.in/id/eprint/59941

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