Characterization of Gallus domesticus alpha-N-acetyl-galactosaminidase blood group A2 activity.

Soluble A antigens and an enzyme-linked immunosorbent assay (ELISA) using type A2 erythrocyte membranes were used to study the activity of an alpha-N-acetyl-galactosaminidase from Gallus domesticus (domestic chicken). The enzyme readily hydrolyzed the terminal N-acetyl-alpha-D-galactosamine of the A antigen under a variety of conditions, converting it to H antigen. Conversion of the A antigen to H antigen produces blood type O, which is universally transfusable. These preliminary studies are important in determining optimal conditions for enzymatic conversion of blood type A to O if efficient large scale production of enzymatically converted, universally transfusable red blood cells is to be achieved.