Synthesis of [formula omitted]: a reactive acceptor analog for N-acetylglucosaminyltransferase-V

• Published in: Carbohydrate research Vol. 271; no. 2; pp. 197 - 205
• Main Authors: Ogawa, Seiichiro, Furuya, Takashi, Tsunoda, Hidetoshi, Hindsgaul, Ole, Stangier, Katja, Palcic, Monica M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1995
• Subjects: N-Acetylglucosaminyltransferase-V; Trisaccharide, carbocyclic analog; N-Acetylglucosaminyltransferase-V; Trisaccharide, carbocyclic analog
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/0008-6215(95)00083-6

The branching enzyme N-acetylglucosaminyltransferase-V (GlcNAcT-V) recognizes the trisaccharide β- d-Glc p NAc-(1 → 2)-α- d-Man p-(1 → 6)-β- d-Glc p- O(CH 2) 7CH 3 (1) as its minimum substrate. We report here the chemical synthesis of β- d-Glc p NAc-(1 → 2)- 5a-carba-α- d-Man p-(1 → 6)-β- d-Glc p- O(CH 2) 7CH 3 (2), a carbocyclic analog of 1 where the ring oxygen of the α- d-Man p residue is replaced by a methylene group. Trisaccharide 2 was found to be fully active as an acceptor for GlcNAcT-V, both with the enzyme isolated from hamster kidney and the one cloned from rat kidney. The kinetic parameters K m and V max for 1 and 2 were functionally equivalent. A preparative glycosylation reaction was performed using 2 as the acceptor with the cloned rat kidney enzyme. A tetrasaccharide formed by the addition of a Glc pNAc residue was the sole product as detected by 1H NMR spectroscopy and FAB mass spectrometry and was assigned the structure β- d-Glc p NAc-(1 → 2)-[β- d-Glc p NAc-(1 → 6)]- 5a-carba-α- d-Man p-(1 → 6)-β- d-Glc p- O(CH 2) 7CH 3 (13).