POLYMERS CONTAINING AMINOSUGARS
497
In type B blood antigens, the galactose residue has a second D-galactose residue attached, through an α1 → 3
linkage. In type A blood antigens, the second sugar residue is now N-acetyl-D-galactosamine, again attached
through an α1 → 3 linkage. It has been found that enzymic removal of the terminal galactose residue from type
B or of the N-acetyl-galactosamine residue from type A converts the B or A antigens into O antigens. It is also
known that individuals with type B or type A antigens possess additional enzyme systems that specifically add
the extra terminal carbohydrate unit to the type O antigen.
497
In type B blood antigens, the galactose residue has a second D-galactose residue attached, through an α1 → 3
linkage. In type A blood antigens, the second sugar residue is now N-acetyl-D-galactosamine, again attached
through an α1 → 3 linkage. It has been found that enzymic removal of the terminal galactose residue from type
B or of the N-acetyl-galactosamine residue from type A converts the B or A antigens into O antigens. It is also
known that individuals with type B or type A antigens possess additional enzyme systems that specifically add
the extra terminal carbohydrate unit to the type O antigen.