STUDIES ON SECRETOR SPECIFIC ACTIVE SITE H (Se) OF HUMAN WATER-SOLUBLE BLOOD GROUP SUBSTANCE

Abstract

1. Blood group H activity against chicken and eel anti-H agglutinins of H substances from human stomach mucosa and ovarian cyst fluid was destroyed by partial alkaline hydrolysis with aqueous methanolic triethylamine. The triethylamine treated H substances lost H(Se) activity against eel anti-H(Se) preicpitin and Le^b activity by partial acid hydrolysis with hydrochloric acid.
2. Three oligosaccharides were isolated from the triethylamine hydolysis products of a H substance from human ovarian cyst. H active and fucose-containing trisaccharide was characterized as α-Fuc-(1→2)-β-Gal-(1→4)-GlcNTAc, which had type II chain.
3. Application of the hydrochloric acid to the partial hydrolysis of the H(Se) substance resulted in the liberation of H (Se) active sugar-peptides. Five oligosaccharides were isolated from the sugar-peptide pool by the treatment of alkaline sodium borohydride. Pentasaccharide containing a- (1→2) -fucosyl residue was characterized as a-Fuc-(1→2)-β-Gal-(1→3)-β-GlcNAc-(1→4)-β-Gal(1→3)-GalNAc, which had type I chain. The pentasaccharide with a β- (1→4) -linkage between N-acetylglucosamine and galactose has not been found in fucose containing oligosaccharides previously isolated and characterized from human blood-group substances. The pentasaccharide did not inhibit the precipitation of anti-H(Se) eel serum but inhibited the agglutination of eel and chicken anti-H. The serological results indicated that the H (Se) activity of the pentasaccharide structure displayed in sugar-peptide or H substance, and eel and chicken anti-H agglutinins could not differentiate α-Fuc-(1→2)-Gal structure of type I and type II oligosaccharides.