How many type of glycoprotein that determine the ABO blood groups are found on the RBC's of human?
In erythrocytes glycoproteins have different oligosaccharide units attached to them. It is these oligosaccharide units which are responsible for determining ABO blood group. So the type of glycoprotein depends upon the oligosaccharide which is attached to it. The core structure is which determines the blood group is same and it is called H-antigen. It is modified in 2 types:
1. H- antigen with have oligosaccharides with a terminal Gal-NAc (Galactose and N-Acetylglucosamine) unit. It is responsible for A blood group.
2. H- antigen with have oligosaccharides with a terminal Gal-Gal unit. It is responsible for B blood group.
Unmodified H-antigen is responsible for O blood group.