光受容レチナ一ルタンパク質の構造機能解析：光+タンパク質=薬！？

摘要

Retinal proteins possess vitamin A aldehyde (retinal) as a chromophore within seven transmembraneひ-helices. Visible light absorption of them triggers trans-cis photoisomerization of the retinal chromophore and induces structural changes in the protein moiety, resulting in a variety of biological functions such as vision, ion transportation, and pho-tosensing. Environmental genomics revealed that retinal proteins are widely distributed through all three biological kingdoms, eukarya, bacteria, and archaea, indicating the biological significance of their light energy conversion. In addition to their biological aspect, retinal proteins have become a focus of interest in part because of applications for opto-genetics. On the basis of our results and other findings, we highlight the recent progress in structural and functional studies on retinal proteins.