Histo-blood group ABO system transferase (ABO transferase)

The histo-blood group ABO system transferase is an enzyme encoded by the ABO gene in humans. It catalyzes the final step in the biosynthesis of ABO blood group antigens by transferring specific monosaccharides onto the H antigen present on glycoproteins and glycolipids at the cell surface. There are several alleles of the ABO gene: the A allele encodes α-1,3-N-acetylgalactosaminyltransferase, which adds N-acetylgalactosamine to generate the A antigen; the B allele encodes α-1,3-galactosyltransferase, adding galactose for the B antigen; and the O allele encodes a non-functional protein, so O group individuals have the unmodified H antigen. The antigenic profile generated by these enzymes determines an individual’s blood group (A, B, AB, or O) and is critical for safe blood transfusion and organ transplantation, as mismatches can produce dangerous immune responses. The ABO system is also epidemiologically associated with risk factors for some diseases outside immunohematology, such as cardiovascular disease.

Other names

ABO glycosyltransferaseABO transferaseBlood group ABO glycosyltransferaseA-transferaseB-transferase