IMMUNOCHEMICAL STUDIES ON BACTERIAL B BLOOD GROUP ACTIVE SUBSTANCES

Abstract

1) An immunologically specific loss variant (B-loss) was isolated from antiserum-containing media by successive inoculation of Escherichia coli O86 wild strain, which has specific O-somatic antigen common to human B blood group substance. The results of haemagglutination inhibition test and precipitation test showed the contribution of (N-acetyl-) D-galactosamine to the determinant group of B-loss variant.2) Chemical analyses and comparison of sugar constituents of the lipopolysaccharides extracted from wild (S), B-loss and rongh (R) strains have demonstrated that O-somatic side chain of E. coli O86 was built up mainly with galactose, fucose and N-acetylgalactosamine.3) The α-galactosidase preparation either from Clostridium maebashi or coffee beans reduced blood group B acvity and also released galactose from S-lipopolysaccharide or B active oligosaccharides obtained by partial acid hydrolysis of its lipopolysaccharide. The degraded lipopolysaccharide showed significant O (H) activity indicating the presence of terminal α-fucosyl moiety in it. An oligosaccharide (A-3) has demonstrated the same activity after enzymatic hydrolysis of α-galactosyl linkage. α-Fucosidase derived from Bacillus fulminans caused to liberate fucose from the a-galactosidase-treated substances and to disappear consequently its O (H) activity.4) The results of quantitative analyses, borohydride reduction, direct Morgan-Elson reactions and treatments with several kinds of enzyme preparations on a series of oligosaccharides indicated that the structure of O-specific side chain of E. coli O86 is probably : α-D-Gal- (1→3) -β-D-Gal→D-GalNAc- (1→3) -D-GalNAc- (1→4) -Fuc↑2↑-1α-L-Fuc (β-D-Glc) 5) B activity of S. milwaukee S-lipopolysaccharide was reduced by treatment with α-galactosidase preparation preparation either from Cl. maebashi or coffee beans, and concomitant. occur-rence of O (H) activity was manifested in the anti O (H) -O red cells system. α-Fuccsidase abolished this activity causing liberation of fucose from the molecule. β-Galactosidase have affected only after hydrolysis of α-fucosyl linkage.It was evident that there was a similality in the terminal structure of lipopolysaccharides of E. coli O86, S. milwaukee and human B blood group substance.