Novel acetylation-aided migrating rearrangement of uridine-diphosphate-N-acetylglucosamine in electrospray ionization multistage tandem mass spectrometry

J Mass Spectrom. 2006 Feb;41(2):208-15. doi: 10.1002/jms.979.


Uridine 5'-diphospho-N-acetylglucosamine (UDP-GlcNAc) is the final product of hexosamine biosynthetic pathway (HSP) and the donor substrate for the modification of nucleocytoplasmic proteins at serine and threonine residues with N-acetylglucosamine (GlcNAc) catalyzed by O-GlcNAc transferase (OGT). Many analogs of UDP-GlcNAc were designed to interfere with the process of protein O-glycosylation by blocking OGT. A novel rearrangement reaction was observed in which phosphate-N-acetylglucosamine moiety migrated to 3' terminus of ribose in ESI-MS(n) of UDP-GlcNAc. Results from tandem mass spectrometry, control experiments and calculation showed that the phosphate-N-acetylglucosamine migration might undergo a pentacoordinate phosphoric intermediate. Furthermore, the acetylation of glucosamine in UDP-GlcNAc was essential in the migration process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Models, Molecular
  • Spectrometry, Mass, Electrospray Ionization
  • Uridine Diphosphate N-Acetylglucosamine / analysis
  • Uridine Diphosphate N-Acetylglucosamine / chemistry*


  • Uridine Diphosphate N-Acetylglucosamine