Sakamoto M, Wada A, Akai A, Ito M, Goshima T, Takahashi T
School of Materials Science, Japan Advanced Institute of Science and Technology, Tatsunokuchi, Ishikawa.
FEBS Lett. 1998 Sep 4;434(3):335-8. doi: 10.1016/s0014-5793(98)01004-7.
Previous studies using retinal analogs (Wada, A., Sakai, M., Kinumi, T., Tsujimoto, K., Yamauchi, M. and Ito, M. (1994) J. Org. Chem. 59, 6992-6997; Wada, A., Sakai, M., Imamoto, Y., Shichida., Y., Yoshizawa, T. and Ito, M. (1993) Chem. Pharm. Bull. 41, 793-795) revealed that both retinochrome and visual pigments share a common chromophoric conformation in which the ring region of retinal is twisted ca. 50 degrees with respect to the plane of the polyene chain, suggesting a highly conserved 6-s-cis conformation throughout rhodopsin-like pigments in animals. By contrast, 6-s-trans conformation was commonly observed or suggested in archaebacterial rhodopsins examined thus far. Here we have reconstituted in vivo both the photoreceptor for photobehavioral responses of the unicellular alga Chlamydomonas reinhardtii and the second archaeal sensory photoreceptor phoborhodopsin from a series of retinal analogs. Results exclusively point to the conclusion that in both photoreceptors retinal has the coplanar 6-s-trans conformation, though recent molecular cloning studies revealed no homology between Chlamydomonas photoreceptor (chlamyrhodopsin) and archaeal rhodopsins.
以往使用视网膜类似物的研究（和田，A.，酒井，M.，木沼，T.，辻本，K.，山内，M.和伊藤，M.（1994年）《有机化学杂志》59，6992 - 6997；和田，A.，酒井，M.，今本，Y.，志田，Y.，吉泽，T.和伊藤，M.（1993年）《化学与药学通报》41，793 - 795）表明，视紫红质和视觉色素都具有共同的发色团构象，其中视网膜的环区域相对于多烯链平面扭曲约50度，这表明在动物中整个视紫红质样色素存在高度保守的6 - s - 顺式构象。相比之下，在迄今为止检测的古细菌视紫红质中通常观察到或推测存在6 - s - 反式构象。在这里，我们用一系列视网膜类似物在体内重建了单细胞藻类莱茵衣藻的光行为反应光感受器以及第二种古细菌感官光感受器嗜盐视紫红质。结果唯一指向的结论是，在这两种光感受器中视网膜都具有共面的6 - s - 反式构象，尽管最近的分子克隆研究表明莱茵衣藻光感受器（衣藻视紫红质）和古细菌视紫红质之间没有同源性。
