Clostridium perfringens alpha-N-acetylgalactosaminidase blood group A2-degrading activity.

Enzymic modification of type A(2) erythrocyte membranes with Clostridium perfringens alpha-N-acetylgalactosaminidase was investigated. An ELISA demonstrated hydrolysis of type A(2) epitopes under conditions of red-blood-cell collection and storage. The enzyme hydrolysed the terminal N-acetyl-alpha-D-galactosamine from the blood type A(2) antigen, producing H antigen, blood group O, which is universally compatible in the ABO system. The enzyme was active in common red-cell preservative solutions at pH 6.4-7.0, at 4 degrees C, at ionic strengths found in stored red cell units and in the presence of type A plasma. These data imply that the C. perfringens alpha-N-acetylgalactosaminidase might be added directly to packed A(2) red-blood-cell units for enzymic conversion to blood type O. Further studies are warranted.