Low‐temperature spectrophotometry of phoborhodopsin

FEBS Letters

Imamoto, Yasushi¹  Takahashi, Tetsuo¹  Tomioka, Hiroaki¹  Yoshizawa, Tôru¹  Shichida, Yoshinori¹  Kamo, Naoki¹  Kobatake, Yonosuke¹ 

[1] Department of Biophysics, Faculty of Science, Kyoto University, Kyoto 606 and Department of Biophysics, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060, Japan

关键词: Phoborhodopsin;    Photochemical reaction;    Primary intermediate;    Low-temperature spectrophotometry;    (Halobacterium halobium);    Pipes;    1;    4-piperazinediethanesulfonic acid;   

DOI  :  10.1016/0014-5793(88)80050-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Photoreactions of the fourth rhodopsin-like pigment, phoborhodopsin (pR480), of Halobacterium halobium were studied by low-temperature spectrophotometry. Upon irradiation of pR480 at - 80 as well as - 170°C with 436 nm light, a new intermediate having a difference absorption maximum at about 520 nm was produced. We designate this intermediate 'P520'. Prolonged irradiation caused the formation of a photosteady-state mixture composed of P520 and pR480, indicating that P520 was photoreversible to pR480 at - 80°C. P520 was thermally converted back to pR480 through P350 and P530, both of which were detected previously [(1986) Biochem. Biophys. Res. Commun. 139, 389–395]. Based on these results, a new photochemical reaction cycle of pR is presented.

【 授权许可】

Unknown