UNIT 12.11 Use of CID/ETD Mass Spectrometry to Analyze Glycopeptides

  1. Yehia Mechref

Published Online: 1 APR 2012

DOI: 10.1002/0471140864.ps1211s68

Current Protocols in Protein Science

Current Protocols in Protein Science

How to Cite

Mechref, Y. 2012. Use of CID/ETD Mass Spectrometry to Analyze Glycopeptides. Current Protocols in Protein Science. 68:12.11:12.11.1–12.11.11.

Author Information

  1. Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas

Publication History

  1. Published Online: 1 APR 2012
  2. Published Print: APR 2012


Collision-induced dissociation (CID) tandem mass spectrometry (MS/MS) does not allow the characterization of glycopeptides because of the fragmentation of glycan structures and limited fragmentation of peptide backbones. Electron transfer dissociation (ETD) MS/MS, on the other hand, offers a complementary approach, prompting only peptide backbone fragmentation while keeping post-translational modifications intact. Characterization of glycopeptides using both CID and ETD is summarized in this unit. While CID provides information related to the composition of glycan moieties attached to a peptide backbone, ETD permits de novo sequencing of peptides. Radical anion transfer of electrons to the peptide backbone in ETD induces cleavage of the N-Cα bond. The glycan moiety is retained on the peptide backbone, largely unaffected by the ETD process, thus allowing the identification of the amino acid sequence of a glycopeptide and its glycosylation site. This unit discusses the use of both CID and ETD for better characterization of glycopeptides. Curr. Protoc. Protein Sci. 68:12.11.1-12.11.11. © 2012 by John Wiley & Sons, Inc.


  • tandem mass spectrometry;
  • ETD;
  • CID;
  • glycoproteins;
  • glycopeptides