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A scheme of immunization of rabbits with partially purified GTP-binding proteins isolated from ox retinal photoreceptor membranes has been developed. Using double radial immunodiffusion, it was shown that rabbit antiserum interacts with the GTP-binding proteins of the retinal phosphoreceptor membranes of ox, pig and frog. The antibodies interaction with the GTP-binding proteins of ox retinal rod outer segments was followed by immunoelectrophoresis as well as by elimination of the activating effect of the non-hydrolyzable derivative of GTP, guanyl-5'-yl-imidodiphosphate on cyclic nucleotide phosphodiesterase in illuminated photoreceptor membranes and in their extracts. A similar effect was exerted by immunoglobulins from immunized animals on the enzyme activation by NaF. Purified immunoglobulins type G did not practically interact with the GTP-binding proteins of the photoreceptor membranes.

It was found that antibodies specifically raised against GTP-binding proteins of bovine retina photoreceptor membranes block the inhibiting effect of estradiol on phosphodiesterase from human and rat uterus cytosol and prevent the combined effect of catecholamines and guanylyl-5'-imidodiphosphate on rat skeletal muscle adenylate cyclase. Using double radial immunodiffusion, it was demonstrated that the antibodies form a precipitating complex with purified tubulin from bovine brain as well as with retinal preparations obtained from the visual organs of ox, pig, rat, frog, some fish species and one reptile species. No appearance of a precipitation band was observed, when retinal preparations of invertebrates (squid, octopus) were used as antigens. The antibodies interacted with the alpha- and beta-subunits of GTP-binding proteins of bovine retinal photoreceptor membranes.