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

✍ Scribed by Hua-Dong Liu; Yan-Mei Li; Jin-Tang Du; Jia Hu; Yu-Fen Zhao

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 217 KB
• Volume: 41
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.979

✦ Synopsis

Abstract

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. Copyright © 2005 John Wiley & Sons, Ltd.