Enzymatic synthesis of a neoglycoconjugate by transglycosylation with Arthrobacter endo-β-N-acetylglucosaminidase: A substrate for colorimetric detection of endo-β-N-acetylglucosaminidase activity

Abstract

The transglycosylation activity of endo-β-N-acetylglucosaminidase from Arthrobacter protophormiae was used for the enzymatic synthesis of a novel oligosaccharide, Man6GlcNAc-p-nitrophenylα-D-glucose (Man6GlcNAc-Glc- pNP). The reaction was efficiently induced in aqueous solution containing dimethyl sulfoxide. In the medium containing 20% (v/v) dimethyl sulfoxide with 0.1 M Glc-pNP as an acceptor, the transglycosylation attained yields of 75% by high-performance anion-exchange chromatography. The structure of Man6GlcNAc-Glc-pNP was confirmed by ion mass spectrometry and 400 MHz 1H NMR specrometry. Various endo-β-N-acetylglucosaminidases hydrolyzed this oligosaccharide and Man6GlcNAc and Glc-pNP were released from the oligosaccharide by endo-β-N-acetylglucosaminidase digestion. We have established a new procedure for the colorimetric detection of endo-βN- acetylglucosaminidase activity using Man6GlcNAc-Glc-pNP, which is simple as that for other exoglycosidase assays with pNP-glycosides as substrates.