EXPRESSION OF MAJOR SIALOGLYCOPROTEIN (GLYCOPHORIN) ON ERYTHROID CELLS IN HUMAN BONE-MARROW

Abstract

The major sialoglycoprotein of human erythrocyte membranes (glycophorin) is one of the most-studied membrane proteins. Although the structure is relatively well known, almost nothing is known about its expression in erythroid cells. To study this an antiserum was raised that reacted specifically with this protein. This was accomplished by immunization of rabbits with a preparation of glycophorin followed by absorption with En(a-) erythrocyte membranes, which lack glycophorin. By use of this antiserum and a Staphylococcus protein A technique, it was established that only bone marrow cells of erythrocyte lineage express glycophorin at the cell surface. This occurs in basophilic normoblasts and later stages of erythrocyte differentiation; pronormoblasts do not seem to contain glycophorin.