alpha-N-acetylgalactosaminidase/NAGA: ProductsThe ABO blood group system is the most important blood type system and alpha-N-acetylgalactoside is key to the ABO blood group antigen. alpha-N-acetylgalactosidase from Clostridium perfringens is a useful tool for removing alpha linked N-acetylgalactosamine from blood type A antigen to produce H antigen and blood type O. Blood type O is universally compatible in the ABO system and is widely used in blood transfusion. The enzyme was highly selective for terminal N-acetylgalactosamine residues. No other exoglycosidase activities, particularly neuraminidase, was detected. Recombinant alpha-N-acetylgalactosidase from Clostridium perfringens can potentially be used in enzymatic conversion of human blood type A red blood cells to universally transfusable type O red blood cells.