title: Structure of asparagine-linked oligosaccharides of an aspartic proteinase from the zygomycete fungus Rhizomucor pusillus.
abstract: The zygomycete fungus Rhizomucor pusillus (previously called Mucor pusillus) secretes an aspartic proteinase containing two asparagine-linked, high-mannose type oligosaccharide chains at Asn79 and Asn188. For structural elucidation of the carbohydrate moieties, the protein was divided into two portions, an N-terminal portion containing Asn79 and a C-terminal portion containing Asn188, by a specific autocatalytic cleavage under alkaline conditions. Each of the asparagine-linked oligosaccharides was then released by peptide-N-glycosidase F digestion and pyridylaminated with a fluorescent reagent, 2-aminopyridine, at the reducing end. High-performance liquid chromatography analyses showed that the structure of the asparagine-linked oligosaccharide chain attached to residue Asn79 was Man5GlcNAc2, and that bound to residue Asn188 was Man5GlcNAc2 and Man6GlcNAc2. These observations suggest that the processing of mannose residues in asparagine-linked oligosaccharides in the Golgi apparatus of Rhizomucor resembles that in mammalian cells.
authors.affiliation: Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Murakami
authors.affiliation: Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Takeuchi
authors.affiliation: Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Beppu
authors.affiliation: Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan.
authors.forename: Sueharu
authors.initials: S
authors.lastname: Horinouch
mesh_terms: D001216:Asparagine / Q000737:chemistry*; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry* / Q000302:isolation & purification; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D006020:Glycopeptides / Q000302:isolation & purification; D008358:Mannose / Q000737:chemistry; D008969:Molecular Sequence Data; D009089:Mucor / Q000201:enzymology*; D009844:Oligosaccharides / Q000737:chemistry*
chemical_list: D006020:Glycopeptides; D009844:Oligosaccharides; D001216:Asparagine; D016282:Aspartic Acid Endopeptidases; D008358:Mannose