Action of Glycosyl Transferases upon “Bombay” (Oh) Erythrocytes: Conversion to Cells Showing Blood‐Group H and A Specificities

Abstract

Individuals of the rare “Bombay” (Oh) blood‐group phenotype are lacking, due to a genetic defect, the α(1—2)fucosyl transferase, which is responsible for converting blood‐group H precursor substances to H‐specific structures. Treatment with GDP‐fucose and β(1—2)fucosyl transferase prepared from gastric mucosa of O individuals failed to transform native or ficin‐treated “Bombay” erythrocytes into cells phenotypically resembling O cells. The transformation was achieved, however, after prior incubation of the “Bombay” erythrocytes with neuraminidase, indicating that blood‐group H precursor molecules on the surface of these cells are masked by sialyl residues. Blood‐group A specificity was conferred upon neuraminidase‐treated “Bombay” cells by enzymatic transfer of α‐N‐acetylgalactosamine residues, in addition to α‐fucose residues. Copyright © 1975, Wiley Blackwell. All rights reserved