7,9-二顺式视紫红质和9,11-二顺式-12-氟视紫红质光漂白中的不同途径：单光子双键和单光子单键异构化

Divergent pathways in photobleaching of 7,9-dicis-rhodopsin and 9,11-dicis-12-fluororhodopsin: one-photon-two-bond and one-photon-one-bond isomerization.

作者信息

Zhu Y, Liu R S

机构信息

Department of Chemistry, University of Hawaii, Honolulu 96822.

出版信息

Biochemistry. 1993 Sep 28;32(38):10233-8. doi: 10.1021/bi00089a045.

DOI:10.1021/bi00089a045

PMID:8399151

Abstract

Through low-temperature photochemistry, UV/vis spectroscopy, and chromophore extraction experiments, we have established that 7,9-dicis-rhodopsin undergoes one-photon-two-bond photoisomerization to a batho intermediate (its absorption maximum is slightly blue shifted from that of bathorhodopsin) containing the all-trans geometry, while 9,11-dicis-12-fluororhodopsin undergoes one-photon-one-bond isomerization to the corresponding 9-cis isomer and then the all-trans batho intermediate. The difference in the photochemical properties of the two dicis pigment analogs was rationalized by possible local protein perturbation, lability of the 11-cis geometry, and photochemical properties of the chromophores.

摘要

通过低温光化学、紫外/可见光谱和发色团提取实验，我们已经确定7,9-二顺式视紫红质经历单光子双键光异构化形成含有全反式几何结构的嗜热中间体（其吸收最大值相对于嗜热视紫红质略有蓝移），而9,11-二顺式-12-氟视紫红质经历单光子单键异构化形成相应的9-顺式异构体，然后再形成全反式嗜热中间体。两种二顺式色素类似物光化学性质的差异可通过可能的局部蛋白质扰动、11-顺式几何结构的不稳定性以及发色团的光化学性质来解释。