Novel acetylation-aided migrating rearrangement of uridine-diphosphate-N-acetylglucosamine in electrospray ionization multistage tandem mass spectrometry.
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.
Liu
Hua-Dong
HD
Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
Li
Yan-Mei
YM
Du
Jin-Tang
JT
Hu
Jia
J
Zhao
Yu-Fen
YF
D000107:Acetylation; D008958:Models, Molecular; D021241:Spectrometry, Mass, Electrospray Ionization; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000032:analysis / Q000737:chemistry*
D014537:Uridine Diphosphate N-Acetylglucosamine