Temperature- and light-dependent structural changes in rhodopsin-lipid membranes

Purified, regenerable rhodopsin has been incorporated into bilayers of synthetic phospholipids. The two-dimensional distribution of rhodopsin molecules in these membranes depends on the composition and state of the hydrocarbon chains. Reversible separations of pure solid lipid and rhodopsin-rich phases have been observed in membranes with a defined composition. The distribution and phase behavior of the protein is altered by bleaching.Freeze-fracture studies of native photoreceptor membranes lend support to the notion that rhodopsin is a transmembrane protein.