Enzyme Actions on the Blood Group H-, Leb-, and Lea-Active Oligosaccharides Isolated from H and Lea Substances

Trisaccharide, having blood group H activity, was obtained from H substance. When the H-active trisaccharide was acted on by the enzyme (α-L-fucosidase) from Bac. Fulminans, fucose was liberated from it, thus losing its H activity and being reduced in the antigenicity common to Sh. dysenteriae, but retaining that common to D. pneumoniae Type XIV. The trisaccharide was split by the enzymes (α-L-fucosidase and β-D-galactosidase) from Bac. cereus H into the component sugars.When the enzyme (α-(1→2)-L-fucosidase) from Bac. fulminans was applied on a Leb-active oligosaccharide, fucose was liberated from it, and Leb-activity was lost to be replaced by Lea-activity.A weak Lea-active trisaccharide obtained from Lea substance was decomposed by the enzymes from Bac. cereus Lea into monosaccharides, fucose, galactose and N-acetylglucosamine.