Actinic light density dependence of the O intermediate of the photocycle of bacteriorhodopsin

FEBS Letters

Tokaji, Zsolt²  Dancsházy, Zsolt²  Luchian, Tudor¹ 

[1] Faculty of Physics, ‘Al. I. Cuza’ University, Bl. Copou 11., Iasy, RO-6600, Rumania;Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, PO Box 521, H-6701 Szeged, Hungary

关键词: Halobacterium halobium;    Light intensity dependence;    M intermediate decay;    Parallel pathways;    Photocycle model;    Photocooperativity;    BR;    bacteriorhodopsin;    Mf;    Ms;    N and O;    intermediates of the photocycle;   

DOI  :  10.1016/0014-5793(96)00391-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The O intermediate of the photocycle of bacteriorhodopsin (BR) was studied by absorption kinetic measurements at different actinic light densities. With increasing exciting flash intensity, the relative yield of O slightly increases, while that of M_f strongly decreases at the expense of M_s. Kinetic calculations and the optical anisotropy of O show that O can be formed only from M_f although M_f and O have different light intensity dependences. In order to resolve the apparent contradiction, a phenomenologically new cooperative regulatory mechanism seems to be necessary.

【 授权许可】

Unknown