Changes in the intramembrane viscosity of sheep erythrocytes in the presence of membrane bound proteins.

Some dynamic properties of protein- and antibody-treated cell membranes were investigated. The membrane viscosity of sheep erythrocytes increased upon binding various proteins as determined from the fluorescence emission anisotropy of 1,6-diphenyl 1,3,5-hexatriene dissolved in the membranes. However, specific, IgM type immunoglobulins produced against the erythrocytes decreased the intramembrane viscosity of cells. The applicability of the above dye to follow the binding of specific and non-specific proteins to erythrocytes is also discussed.