About this Biochemistry, Genetics and Molecular Biology article

The Origin and Control of ** Ex Vivo ** Oxidative Peptide Modifications Prior to Mass Spectrometry Analysis by Jennifer M. Froelich; Gavin E. Reid is a Biochemistry, Genetics and Molecular Biology article available to read on EtoBox.

## Abstract The origin and control of __ex vivo__ sample handling related oxidative modifications of methionine‐, __S__‐alkyl cysteine‐, and tryptophan‐containing peptides obtained from typical “in‐solution” or “in‐gel” proteolytic digestion strategies, have been examined by capillary HPLC and MS/MS. The origin of increased oxidation levels were found to be predominantly associated with the extensive __ex vivo__ sample handling steps required for gel electrophoresis and/or in‐gel proteolytic digestion of proteins prior to analysis by MS. Conditions for deliberately controlling the oxidation state (both oxidation and reduction) of these peptides, as well as for those containing cysteine, have been evaluated using a series of model synthetic peptides and standard tryptic protein digests. Essentially complete oxidation of methionine‐ and __S__‐alkyl cysteine‐containing peptides was achieved by reaction with 30% hydrogen peroxide/5% acetic acid at room temperature for 30 min. Under these conditions, cysteine was also converted to cysteic acid, while only limited oxidation of tryptophan to oxindolylalanine, and methionine and __S__‐alkyl cysteine sulfoxides to their respective sulfones,

Author

Jennifer M. Froelich; Gavin E. Reid

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); John Wiley & Sons Ltd.; Wiley; Research Square (ISSN 1615-9853)

Published

2008

Language

EN

Field

Biochemistry, Genetics and Molecular Biology (Life Sciences)