title: Isolation, partial characterization and biological activity of mannosyl glycopeptides from seminal plasma.
abstract: Affinity chromatography on Concanavalin-A Sepharose, followed by gel filtration and hydrophobic interaction chromatography, permits the isolation of low molecular weight N-glycosidically linked oligomannosidic glycopeptides (MGp) from the autoproteolysis products of human seminal plasma. The monosaccharide composition of MGp showed only mannose, N-acetylglucosamine and a small amount of galactose. Structural studies were carried out by methylation analysis and chromium trioxide oxidation, and results were consistent with the structures accepted for high-mannose N-glycans. MGp was capable of inhibiting the sperm acrosomal exocytosis mediated by sperm-surface receptors. These data suggest that MGp act as a "decapacitation" factor preventing premature sperm exocytosis.
authors.affiliation: Departamento de Bioquímica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: C H
authors.initials: CH
authors.lastname: Lopes
authors.forename: M N
authors.initials: MN
authors.lastname: Mazzini
authors.forename: H
authors.initials: H
authors.lastname: Tortorella
authors.forename: R A
authors.initials: RA
authors.lastname: Konrath
authors.forename: A
authors.initials: A
authors.lastname: Brandelli
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects; D002236:Carbohydrate Conformation; D002846:Chromatography, Affinity; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D005089:Exocytosis; D006020:Glycopeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D008297:Male; D008358:Mannose / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry; D012661:Semen / Q000737:chemistry*
chemical_list: D006020:Glycopeptides; D009844:Oligosaccharides; D008358:Mannose