Thermal stability of rhod opsin and protein lipid interactions in the photo receptor membranes of homoiothermic and poikilothermic animals
Tyurin, V.A.; Kagan, V.E.; Shukolyukov, S.A.; Klaan, N.K.; Novikov, K.N.; Azizova, O.A.
Journal of Thermal Biology 4(3): 203-208
ISSN/ISBN: 0306-4565 DOI: 10.1016/0306-4565(79)90002-0
The interrelationship between thermal stability of rhodopsin and the amount of immobilized lipids as well as the fluidity of lipids in the photoreceptor membranes (PRM) of homoiothermic (ox, Bos taurus) and poikilothermic (frog, Rana temporaria and wall-eyed pollock, Theragra chalcogramma) animal species were studied. The values of thermal denaturation rate constants for rhodopsin at fixed temperatures are directly correlated with the amount of fluid lipids in PRM and are inversely correlated with the amount of lipids immobilized by rhodopsin. Within the range of physiological temperatures (37.degree. C.sbd.ox, 0.degree.-20.degree. C.sbd.frog, 0.degree.-10.degree. C.sbd.wall-eyed pollock) both thermal stability of rhodopsin and fluidity of the lipid bilayer and the amount of lipids interacting with the visual pigment in PRM appear to be very close.