Detection and characterization of methionine oxidation in peptides by collision-induced dissociation and electron capture dissociation

Abstract

Electron capture dissociation (ECD) and collision-induced dissociation (CID), the two complementary fragmentation techniques, are demonstrated to be effective in the detection and localization of the methionine sulfoxide [Met(O)] residues in peptides using Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. The presence of Met(O) can be easily recognized in the low-energy CID spectrum showing the characteristic loss of methanesulfenic acid (CH 3 SOH, 64 Da) from the side chain of Met(O). The position of Met(O) can then be localized by ECD which is capable of providing extensive peptide backbone fragmentation without detaching the labile Met(O) side chain. We studied CID and ECD of several Met(O)-containing peptides that included the 44-residue human growth hormone-releasing factor (GRF) and the human atrial natriuretic peptide (ANP). The distinction and complementarity of the two fragmentation techniques were particularly remarkable in their effects on ANP, a disulfide bond-containing peptide. While the predominant fragmentation pathway in CID of ANP was the loss of CH 3 SOH (64 Da) from the molecular ion, ECD of ANP resulted in many sequence-informative products, including those from cleavages within the disulfidebonded cyclic structure, to allow for the direct localization of Met(O) without the typical procedures for disulfide bond reduction followed by ™SH alkylation. (J Am Soc Mass Spectrom 2003, 14, 605-613)

Oxidation of proteins: Basic principles and perspectives for blood proteomics

“…One promising solution to this problem is the development of "softer" fragmentation techniques such as electron transfer dissociation (ETD) and electron capture dissociation (ECD). For example, Guan et al [129] showed that CID of oxidised methionine containing peptides resulted in the loss of CH 3 SOH whereas ECD allowed fragmentation of the peptide backbone while preserving the side-chain oxidation, thus allowing direct location of the oxidised methionine.…”

Oxidation Artifacts in the Electrospray Mass Spectrometry of Aβ Peptide

“…Methionine is one of the most readily oxidized amino acid constituents of proteins [5,[11][12][13]. Oxidation of methionine residues can result in significant conformational and/or functional changes [14], and thus represents an important posttranslational modification under conditions of oxidative stress or aging [15].…”

Natural structural motifs that suppress peptide ion fragmentation after electron capture

“…These hydrogen bonds would provide extra stabilization for [Mϩ2H] -4]. ECD also plays a useful role in characterization and localization of post-translational modifications (PTMs) as it preserves labile PTMs in protein [5][6][7] while cleaving the protein backbone to give series of specific fragment ions. This is in contrast with that of conventional slow-heating ion dissociation methods [8,9], such as collision induced dissociation (CID) [10 -12] and infrared multiproton dissociation (IRMPD) [13].…”

“…(J Am Soc Mass Spectrom 2010, 21, 1235-1244) © 2010 Published by Elsevier Inc. on behalf of American Society for Mass Spectrometry E lectron capture dissociation (ECD) is an important tandem mass spectrometry (MS/MS) tool for sequencing multiply-charged peptides/proteins [1][2][3][4]. ECD also plays a useful role in characterization and localization of post-translational modifications (PTMs) as it preserves labile PTMs in protein [5][6][7] while cleaving the protein backbone to give series of specific fragment ions. This is in contrast with that of conventional slow-heating ion dissociation methods [8,9], such as collision induced dissociation (CID) [10 -12] and infrared multiproton dissociation (IRMPD) [13].…”