Low-temperature femtosecond spectroscopy of the initial step of electron transfer in reaction centers from photosynthetic purple bacteria
Low-temperature femtosecond spectroscopy of the initial step of electron transfer in reaction centers from photosynthetic purple bacteria
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光合紫色细菌反应中心电子转移初始步骤的低温飞秒光谱
DOI：
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
J. Lambry
中科院分区：
文献类型：
--
作者：
J. Breton;Jean‐Louis Martin;G. Fleming;J. Lambry
在10 K下的电荷分离的初始步骤已监测与100 fs的时间分辨率在反应中心从红球藻和球形红细菌以及在反应中心从后者的物种，其中的两个单体细菌叶绿素（B）分子之一已被删除的处理与硼氢化物。在870 nm处激发时，在颜料的近红外吸收带中的几个波长处测量的吸光度变化，特别是在B分子的最大吸收处，没有给出可检测的B-浓度的指示。相反，二聚初级电子供体（P）的阳离子自由基和细菌脱镁叶绿素阴离子的出现与P* 的衰变一致。来自Rho-dopophylla uiridis的反应中心中的850-nm带的初始漂白与该带的至少大部分归属于P的高能激子分量一致。在所研究的三种类型的反应中心中，在600 nm附近激发B分子时，超快能量转移导致在小于100 fs内形成P*。在这些条件下，观察到一个快速的瞬态漂白衰减与400 fs的时间常数内的吸收带内的B。当铜绿红假单胞菌反应中心的细菌脱镁菌素优先激发时，也会出现这种瞬时现象。
The initial step of charge separation at 10 K has been monitored with 100-fs time resolution in reaction centers from Rhodopseudomonas viridis and Rhodobacter sphaeroides as well as in reaction centers from the latter species in which one of the two monomeric bacteriochlorophyll (B) molecules has been removed by treatment with borohydride. Upon excitation at 870 nm, the absorbance changes measured at several wavelengths in the near-infrared absorption bands of the pigments, and notably at the absorption maximum of the B molecule(s), give no indication of a detectable concentration of B-. Instead, the appearance of the cation radical of the dimeric primary electron donor (P) and of the bacteriopheophytin anion develops in concert with the decay of P*. An initial bleaching of the 850-nm band in reaction centers from Rho- dopseudomonas uiridis is consistent with an assignment of at least a large fraction of this band to the high-energy exciton component of P. Upon excitation of the B molecule(s) around 600 nm in the three types of reaction centers investigated, ultrafast energy transfer leads to the formation of P* in less than 100 fs. Under these conditions, a fast transient bleaching decaying with a 400-fs time constant is observed within the absorption band of B. This transient is also present upon preferential excitation of the bac- teriopheophytins in the reaction center of Rhodopseudomonas uiridis.
DOI：
10.1073/pnas.84.16.5730
发表时间：
1987-08-01
影响因子：
11.1
作者：
ALLEN, JP;FEHER, G;REES, DC
通讯作者：
REES, DC
细菌光合反应中心初始光化学电子转移反应的皮秒动力学。
影响因子：
2.9
作者：
Woodbury,NW;Becker,M;Middendorf,D;Parson,WW
通讯作者：
Parson,WW