[Loosely bound proteins and membrane ultrastructure of erythrocyte ghosts]

The loosely bound erythrocyte ghost proteins, extracted by distilled water, 5 mM EDTA, tris-HCI buffer at pH 8.5, veronal-acetate buffer at pH 8.5 and by a 1.5% solution of acetic acid, were studied electrophoretically using a polyacrilamid gel with 0.1% sodium docecyl sulphate. 20% proteins with m.v.12 000-120 000 polypeptid chains were released from ghosts transferred from phosphate buffer to distilled water. 5 mM EDTA extracts, in addition, a m. w. 215000 protein. The increase of the negative change brought about the extraction of proteins of the molecular weight equal to 12 000-250 000. After extraction of 12% or more loosely bound proteins the reduction of membrane-attached materials was seen with the electron microscope. Shifts of pH from 6.3 to 7.4 and the treatment with 5mM EDTA resulted in reduction of the premembrane material, ghosts sticking together after the latter procedure.