Enzymatic Conversion of Red Cells for Transfusion

摘要

Our interest is in enzymatically converting type A and B erythrocytes to type O under conditions which render them useful in transfusion therapy. We are currently attempting such conversions of A cells using an alpha-N-acetylgalactosamindase (A-zyme) for chicken liver. This enzyme has been purified free of any detectable contaminating proteases, sialidase and other exoglycosidases with the the exception of alpha-galactosidase activity (8-10% of A-zyme) which is believed to be intrinsic and not due to a contaminating enzyme. It can remove A antigenicity from the red cell surface and is considerably more effective in doing so than comparable preparations of A-zyme from the earth worm and sheep. Results are encouraging in that they suggest that A antigenic sites resistant to the action of chicken liver A-zyme are not sterically inaccessible but given the proper enzyme and buffer conditions they too can be removed.