Cysteine tagging for MS-based proteomics

Mass Spectrom Rev. May-Jun 2011;30(3):366-95. doi: 10.1002/mas.20285. Epub 2010 Nov 2.


Amino acid-tagging strategies are widespread in proteomics. Because of the central role of mass spectrometry (MS) as a detection technique in protein sciences, the term "mass tagging" was coined to describe the attachment of a label, which serves MS analysis and/or adds analytical value to the measurements. These so-called mass tags can be used for separation, enrichment, detection, and quantitation of peptides and proteins. In this context, cysteine is a frequent target for modifications because the thiol function can react specifically by nucleophilic substitution or addition. Furthermore, cysteines present natural modifications of biological importance and a low occurrence in the proteome that justify the development of strategies to specifically target them in peptides or proteins. In the present review, the mass-tagging methods directed to cysteine residues are comprehensively discussed, and the advantages and drawbacks of these strategies are addressed. Some concrete applications are given to underline the relevance of cysteine-tagging techniques for MS-based proteomics.

Publication types

  • Review

MeSH terms

  • Animals
  • Cysteine / analysis*
  • Cysteine / chemistry
  • Cysteine / metabolism
  • Humans
  • Mass Spectrometry / methods*
  • Proteome / analysis*
  • Proteome / chemistry
  • Proteome / metabolism
  • Proteomics / methods*


  • Proteome
  • Cysteine