title: Heteronuclear NMR studies of 13C-labeled yeast cell wall beta-glucan oligosaccharides.
abstract: The structures of uniformly 13C-labeled beta-glucan octa- and undeca-oligosaccharides enzymatically prepared by the yeast cell wall glucanosyl transferase of Candida albicans were characterized by using a combination of HCCH-COSY, HCCH-TOCSY, and HMBC experiments. The oligosaccharide structures indicate that the cell wall glucanosyl transferase cleaves two glucosyl units from the reducing end of the initial linear beta(1-->3) penta-oligosaccharide and subsequently transfers the remainder to another oligosaccharide at the nonreducing end via a beta(1-->6) linkage. These results indicate that the combined action of cell wall glucanase and glucanosyl transferase activities could not only introduce intrachain beta(1-->6) linkages within a single glucan strand, but also result in cross-linking of two initially separate glucan strands with concurrent introduction of intrachain beta(1-->6) linkages. Since isolated fungal membranes only synthesize linear beta(1-->3) glucan strands, wall-associated enzymes probably participate in the assembly of the final wall glucan structure during cell growth and division.
authors.affiliation: Pharmaceutical Discovery Division, Abbott Labortories, Abbott Park, IL 60064.
authors.forename: L
authors.initials: L
authors.lastname: Yu
authors.forename: R
authors.initials: R
authors.lastname: Goldman
authors.forename: P
authors.initials: P
authors.lastname: Sullivan
authors.forename: G F
authors.initials: GF
authors.lastname: Walker
authors.forename: S W
authors.initials: SW
authors.lastname: Fesik
mesh_terms: D002176:Candida albicans / Q000737:chemistry; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry; D005936:Glucans / Q000737:chemistry*; D005964:Glucosyltransferases; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D005936:Glucans; D009844:Oligosaccharides; D005964:Glucosyltransferases