The Action of the Blood Group B Gene‐Specified α‐Galactosyltransferase from Human Serum and Stomach Mucosal Extracts on Group O and ‘Bombay’ O_h Erythrocytes

Abstract

Abstract. Human blood group O cells were converted to B‐active cells by incubation with uridine diphosphate d ‐galactose and enzyme preparations from group B stomach mucosa or serum from group B or AB subjects. The specificity of the converted cells was tested by their reaction with human and rabbit anti‐B sera and by the specific inhibition of the newly acquired agglutinating properties by soluble blood group B substance and B‐active oligosaccharides. The failure of the α‐galactosyltransferases to transform cells of the ‘Bombay’ O h phenotype into B‐active cells supports the concept that H‐active structures are the acceptors of the transferred galactosyl residues.