Structural studies of the O-antigen polysaccharides of Klebsiella O5 and Escherichia coli O8.
The O-antigen polysaccharides of Klebsiella serotype O5 and Escherichia coli serotype O8 are serologically very similar or identical. The structures of these two polysaccharides have now been re-investigated. N.m.r. spectroscopy, chromium trioxide oxidation, hydrolysis with a specific phage enzyme, and f.a.b. mass spectrometry were the principal methods used. It is concluded that the O-antigen has the following structure, in which D-Man3Me is 3-O-methyl-D-mannose and n is approximately 10. (Formula: see text) Biosynthetic studies indicate that these antigens are synthesised by addition of D-mannopyranosyl groups to the "non-reducing" end of the mannan chain, and it seems possible that addition of a 3-O-methyl-D-mannopyranosyl group involves termination.
D002236:Carbohydrate Conformation; D002857:Chromium; D017608:Chromium Compounds; D004926:Escherichia coli / Q000276:immunology*; D007202:Indicators and Reagents; D007709:Klebsiella / Q000276:immunology*; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000032:analysis; D013058:Mass Spectrometry; D011135:Polysaccharides, Bacterial; D012703:Serotyping; D013045:Species Specificity
D017608:Chromium Compounds; D007202:Indicators and Reagents; D011135:Polysaccharides, Bacterial; D002857:Chromium; C028801:chromium trioxide; D008358:Mannose