title: Structural studies of the capsular polysaccharide of Acinetobacter calcoaceticus BD4.
abstract: Compositional analysis of the intact and carboxyl-reduced capsular polysaccharide of Acinetobacter calcoaceticus BD4 (PS-4) showed it to consist of L-rhamnose, D-glucose, D-glucuronic and D-mannose in molar ratios of 4:1:1:1. 13C-nuclear magnetic resonance spectroscopy, methylation analysis, oligosaccharide analysis and base-catalyzed beta-elimination were used to elucidate the primary structure. Oligosaccharides were obtained by enzymatic depolymerization with a specific bacteriophage-induced depolymerase and by partial acid hydrolysis. Form the results it is concluded that PS-4 consists of repeating units of the heptasaccharide (Formula: see text). The bacteriophage-induced depolymerase was found to be an endo-beta-D-glucosidase that hydrolyzed the bond beta-D-Glc-(1----3)-L-Rha to generate a heptasaccharide in 40% yield.
mesh_terms: D000150:Acinetobacter / Q000276:immunology*; D002384:Catalysis; D055598:Chemical Phenomena; D002621:Chemistry; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D009844:Oligosaccharides / Q000032:analysis; D010084:Oxidation-Reduction; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D012210:Rhamnose / Q000032:analysis
chemical_list: D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial; D012210:Rhamnose