STUDIES ON RED CELL MEMBRANE PROTEINS Ⅰ. ELECTROPHORETIC PATTERNS OF VARIOUS MEMBRANE PROTEIN EXTRACTS ON POLYACRYLAMIDE DISC GEL ELECTROPHORESIS
Electrophoretic patterns of membrane proteins in mature human red cells were investigated on the SDS-polyacrylamide disc gel electrophoresis. The best resolution of these membrane proteins was obtained on the 11 % gel system with discontinuous buffers. Some of peripheral proteins of red cell membranes were lost either by lysing red cells wish 5 mM P04 buffer (pH 8.0) or by washing red cell ghosts more than three times even with the 20 mOsm Na/K P04-buffered saline (pH 7.4). Contrary to commonly held belief, on the 11 % gel system, a major glycoprotein of red cell membrane proteins (PAS-1) appears to be different from the band III stained by coomassie blue. The electrophoretic patterns consisted mainly of bands I and II in peripheral protein extracts, and of bands of the lower molecular weight including the band III in integral protein extracts, respectively. The SDS polyacrylamide disc gel electrophoresis would be suitable as a preparatory procedure for extraction and purification of specific protein fractions of red cell membrane proteins.