[Some features of rhodopsin regeneration process in the presence of exogenous 11Z-retinal in teleosts].

The rate of rhodopsin regeneration in decolorized rod outer segments ROS of pollock and ruff in the presence of exogenous 11Z-retinal is found to depend slightly on the temperature. The Arrhenius curve is linear within 0--20 degrees C and 0--30 degrees C in case of pollock and black ruff ROS respectively. The increase of the regeneration temperature above the upper limit results in both cases in the decrease of the chromophore binding rate due to the temperature denaturation of fish opsin. The rate of opsin regeneration in bovine ROS is temperature-dependent within 0--50 degrees C, the Arrhenius curves having a specific break with the temperature conversion at 12--13 degrees, which indicates a different 11Z-retinal binding rate with bovine opsin at low and high temperatures. Maximal rhodopsin regeneration temperature was observed within 5--10 min. for fish ROS and 1.5 hour for bovine ROS. Trimethylcyclohexene derivatives with a side chain of about 7 carbon atoms and 13Z-retinal competitively inhibited the rhodopsin regeneration in pollock and bovine ROS, while 13E-11, 12-dehydroretinal and all-E-retinal did not effect this process. Some peculiarities of the rhodopsin regeneration process in fish are discussed in connection with the molecular organization of a lipid phase of photoreceptor membrane and chromophore-binding region.