Effects of ethanol on lateral and rotational mobility of plasma membrane vesicles isolated from cultured mouse myeloma cell line Sp2/0-Ag14.

Intramolecular excimerization of Py-3-Py and fluorescence polarization of DPH were used to evaluate effects of ethanol on the rate and range of the lateral mobility and the range of the rotational mobility of bulk bilayer structures of the Sp2/0-PMV. In a concentration-dependent manner, ethanol increased the rate and range of the lateral mobility and the range of the rotational mobility of bulk bilayer structures of Sp2/0-PMV. Selective quenching of DPH by trinitrophenyl groups was utilized to examine the range of transbilayer asymmetric rotational mobility of the Sp2/0-PVM. The anisotropy (r), limiting anisotropy (r(infinity)) and order parameter (S) of DPH in the inner monolayer were 0.022, 0.029 and 0.063, respectively, greater than calculated for the outer monolayer of the Sp2/0-PMV. Selective quenching of DPH by trinitrophenyl groups was also used to examine the transbilayer asymmetric effects of ethanol on the range of the rotational mobility of the Sp2/0-PMV. Ethanol had a greater increasing effect on the range of the rotational mobility of the outer monolayer as compared to the inner monolayer of the Sp2/0-PMV. It has been proven that ethanol exhibits a selective rather than nonselective fluidizing effect within the transbilayer domains of the Sp2/0-PMV.