title: A novel disaccharide substrate having 1,2-oxazoline moiety for detection of transglycosylating activity of endoglycosidases.
abstract: A disaccharide substrate of Manbeta1-4GlcNAc-oxazoline 2 was designed and synthesized as a novel probe for detection of the transglycosylating activity of endoglycosidases. A regio- and stereoselective transglycosylation reaction of 2 to GlcNAcbeta1-O-pNP or Dns-Asn(GlcNAc)-OH catalyzed by endo-beta-N-acetylglucosaminidase from Mucor hiemalis (Endo-M) and endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (Endo-A) has been demonstrated for the first time, resulting in the core trisaccharide derivative Manbeta1-4GlcNAcbeta1-4GlcNAcbeta1-O-pNP 8 (or -(Dns)Asn-OH). Interestingly, the transglycosylation proceeds irreversibly; the resulting trisaccharide 8 was not hydrolyzed by Endo-M and Endo-A. Based on these results, a new mechanism including an oxazolinium ion intermediate has been proposed for the endoglycosidase-catalyzed hydrolysis or transglycosylation.
authors.affiliation: Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Fujita
authors.forename: S
authors.initials: S
authors.lastname: Shoda
authors.forename: K
authors.initials: K
authors.lastname: Haneda
authors.forename: T
authors.initials: T
authors.lastname: Inazu
authors.forename: K
authors.initials: K
authors.lastname: Takegawa
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis*; D006026:Glycoside Hydrolases / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000737:chemistry; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry; D013379:Substrate Specificity; D014166:Transferases / Q000737:chemistry; D014312:Trisaccharides / Q000138:chemical synthesis
chemical_list: D004187:Disaccharides; D009097:Multienzyme Complexes; D014312:Trisaccharides; C023176:transglycosidase enzyme system; D014166:Transferases; D006026:Glycoside Hydrolases; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase