Abstract
Retinal proteins are now identfied over a thousand spiecies and classfied two family types, animal- and microbial-rhodopsins, from their origin. These proteins consist of the chromophre retinal and a seven-transmembrane helix apoprotein (opsin), and these two components were covalently bonded through a protonated Shiff base. When light energy was absorbed, the double bond isomerization of the chromophore occurred from 11-cis to all-trans in animal rhodopsins and from all-trans to 13-cis in microbial rhodopshins with a conformational structure change of the opsin, and the important biological functions such as vision, isomerization, ion-pumping and cation channels in living cells were performed. In this paper, I would like to briefly overview our investigations of retinal proteins for vision and optogenetics.
