[Fatty acid composition of the bilayer phospholipids in the photoreceptor membranes and aminophospholipids from the rhodopsin microenvironment of warm-blooded and cold-blooded vertebrates]

Abstract

Studies have been made on the distribution of phospholipids between rhodopsin and free lipids of photoreceptor membranes of the outer segments of retinal rods from cattle, frog Rana temporaria and fish Teragra chalcogramma. comparative investigation of fatty acid composition of phospholipids from rhodopsin microboundary and lipid bilayer in photoreceptor membranes was made as well. Amino phospholipids from rhodopsin microboundry were revealed using glutaraldehyde. This reagent by means of its aldehyde groups links phospholipid amino groups with amino groups of proteins of photoreceptor membranes. After this treatment, free phospholipids of lipid bilayer were extracted from photoreceptor membranes by methanol-chloroform mixture. It was demonstrated that fatty acid composition of phospholipids of lipid bilayer differs from that of amino phospholipids from rhodopsin microboundary. In the animals investigated, fatty acids of phospholipids from lipid bilayer were found to be more unsaturated than fatty acids of amino phospholipids from rhodopsin microboundary. This difference was more pronounced in photoreceptor membranes from the frog and fish than from cattle.