Immunochemical Studies on Bacterial Blood Group Substances

The terminal α-galactosyl linkage was hydrolyzed by an enzyme preparation from either Clostridium maebashi or coffee beans. Reduction of blood group B activity of Salmonella milwaukee and Escherichia coli O₈₆ lipopolysaccharides and of some oligosaccharides occurred consequently. The degraded lipopolysaccharides showed significant blood group O (H) activity indicating the presence of terminal α-fucosyl residues in them and the same activity was demonstrated with oligosaccharide A-3 after the enzyme treatment. α-Fucosidase derived from Bacillus fulminans caused liberation of fucose from the α-galactosidasc-treated, materials and abolishment of O (H) activity. The results of quantitative analysis, borohydride reduction, Morgan-Elson reaction and treatments with several kinds of enzyme preparations on a series of oligosaccharides indicated that the structure of O-somatic side chain of E. coli O₈₈ is probably; It was evident that there is a similarity in the terminal structure of lipopolysaccharides of E. coli O₈₆, S. milwaukee and human B blood group substance.