Low-temperature Raman spectroscopy reveals small chromophore distortion in primary photointermediate of proteorhodopsin
Low-temperature Raman spectroscopy reveals small chromophore distortion in primary photointermediate of proteorhodopsin
复制标题
低温拉曼光谱揭示了原视紫红质初级光中间体中的微小发色团畸变
DOI：
10.1002/1873-3468.13219
复制
发表时间：
2018
期刊：
影响因子：
3.5
通讯作者：
Unno Masashi
中科院分区：
文献类型：
--
作者：
Fujisawa Tomotsumi;Abe Masahiro;Tamogami Jun;Kikukawa Takashi;Kamo Naoki;Unno Masashi
前视紫红质（PR）是一种微生物视紫红质，在水生细菌中起光驱动质子泵的作用。我们对PR进行了低温拉曼测量，以获得主要光产物K中间体（K）的结构。PRK显示了氢的平面外模式，其强度远低于细菌视紫红质作为来自盐古菌的原型光驱动质子泵的强度。本研究结果揭示了显着放松的发色团结构的钾中间体，这可以耦合到缓慢的动力学。这种结构表明PR在其光循环开始时使用发色团内的小能量储存来运输质子。
Proteorhodopsin (PR) is a microbial rhodopsin functioning as a light‐driven proton pump in aquatic bacteria. We performed low‐temperature Raman measurements of PR to obtain the structure of the primary photoproduct, the K intermediate (PRK). PRKshowed the hydrogen‐out‐of‐plane modes that are much less intense than those of bacteriorhodopsin as the prototypical light‐driven proton pump from haloarchaea. The present results reveal the significantly relaxed chromophore structure in PRK, which can be coupled to the slow kinetics of the K intermediate. This structure suggests that PR transports protons using the small energy storage within the chromophore at the start of its photocycle.