EVALUATION OF EXPERIMENTALLY-INDUCED ENZYMATIC ALTERATIONS ON THE ERYTHROCYTE-MEMBRANE BY USE OF ALCIAN BLUE

The binding of the polycationic dye alcian blue to erythrocytes is inv estigated at pH 6 and pH 3 after treatment with neuraminidase and prot eolytic enzymes. The portion of the dye bound by membrane-negative cha rge-carriers, as well as by hydrophobic interactions with mainly membr ane protein compounds, is calculated. It is demonstrated that not only the sialic acid, as the main negative charge domain, but also protein s are interacting with the dyestuff. Proteolytically split membrane fr agments contain a considerable amount of alcian blue that cannot be as sociated with the estimated sialic acid content.