Electrostatic and structural properties of the surface of human erythrocytes. 3. Cell electrophoretical studies following addition of human serum albumin.

It has been shown that human serum albumin (HSA) under physiological conditions does not affect the electrophoretical properties of human erythrocytes. In contrast, albumin at low ionic strengths and low pH-values progressively reduces the electrophoretical mobility up till a reversal of the erythrocytes' movement with simultaneous aggregation. Zero mobility is strongly ionic strength dependent; this property cannot be explained by the ionic strength dependence of the isoelectric point of HSA. It is concluded that the HSA is bound to the lipid matrix. This offers an explanation that the influence of HSA becomes electrophoretically demonstrable particularly at low ionic strengths. The identification limit of alterations induced by HSA corresponds to the physiological concentrations of HSA in blood.