Further Studies on the Membrane Glycoprotein Defects of S — s — and En(a-)-Erythrocytes

Abstract

Sodium dodecylsulfate polyacrylamide gel electrophoretic methods were applied to S-s- and En(a-) red cells and to erythrocytes from individuals heterozygous for these defects. The results demonstrate, more conclusively than previous data, that the glycosylated part of the MN glycoprotein is lacking in En(a-) red cell membranes. S-s-U- erythrocytes lack the Ss glycoprotein completely or contain a defective molecule which is devoid of the glycosylated part. S-s-U+ cells exhibit small amounts of Ss glycoprotein which could only be detected when large amounts of extracted glycoproteins were separated. This molecule possesses the N antigenic determinant.