The defect of Mk erythrocytes as revealed by sodium dodecylsulphate--polyacrylamide gel electrophoresis.

The membrane glycoprotein defect of Mk red cells was studied using discontinuous sodium dodecylsulphate--polyacrylamide gel electrophoresis, carbohydrate analytical procedures and lectins. The results suggest that Mk erythrocyte membranes contain only about half of the normal amount of the MN and Ss sialoglycoproteins, both molecules being not qualitatively different from normal. The major membrane protein exhibits an increased molecular weight in the above red cells. Some data on Mg and Miltenberger class five cells are presented for comparison. The results on Mk erythrocytes support the operon concept of the MNSs blood group system proposed previously.