Shotgun redox proteomics: identification and quantitation of carbonylated proteins in the UVB-resistant marine bacterium, Photobacterium angustum S14

PLoS One. 2013 Jul 9;8(7):e68112. doi: 10.1371/journal.pone.0068112. Print 2013.

Abstract

UVB oxidizes proteins through the generation of reactive oxygen species. One consequence of UVB irradiation is carbonylation, the irreversible formation of a carbonyl group on proline, lysine, arginine or threonine residues. In this study, redox proteomics was performed to identify carbonylated proteins in the UVB resistant marine bacterium Photobacterium angustum. Mass-spectrometry was performed with either biotin-labeled or dinitrophenylhydrazide (DNPH) derivatized proteins. The DNPH redox proteomics method enabled the identification of 62 carbonylated proteins (5% of 1221 identified proteins) in cells exposed to UVB or darkness. Eleven carbonylated proteins were quantified and the UVB/dark abundance ratio was determined at both the protein and peptide levels. As a result we determined which functional classes of proteins were carbonylated, which residues were preferentially modified, and what the implications of the carbonylation were for protein function. As the first large scale, shotgun redox proteomics analysis examining carbonylation to be performed on bacteria, our study provides a new level of understanding about the effects of UVB on cellular proteins, and provides a methodology for advancing studies in other biological systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Computational Biology / methods
  • Mass Spectrometry
  • Models, Molecular
  • Oxidation-Reduction
  • Photobacterium / metabolism*
  • Photobacterium / radiation effects
  • Protein Carbonylation
  • Protein Structure, Tertiary
  • Proteome*
  • Proteomics* / methods
  • Reactive Oxygen Species / metabolism
  • Staining and Labeling
  • Ultraviolet Rays

Substances

  • Bacterial Proteins
  • Proteome
  • Reactive Oxygen Species

Grants and funding

This work was supported by the European community project MAMBA (FP7-KBBE-2008-226977). Research in RC and MJRs laboratories was supported by the Australian Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.