[Structural stabilization of lipids and visual pigment rhodopsin in the photoreceptor membrane by vitamin E]

Interaction of alpha-tocopherol with free fatty acids in bovine retinal photoreceptor membranes was studied using ESR spin-probe technique and measurements of rhodopsin thermal denaturation rates. Exogenous alpha-tocopherol incorporated into photoreceptor membranes prevented thermal destabilization of rhodopsin caused by free fatty acids. The efficiency of the stabilizing action of alpha-tocopherol directly depended both on the chain length and the degree of fatty acid unsaturation.