Influence of Hydrogen Bonds on the Electron-Phonon Coupling Strength/Marker Mode Structure and Charge Separation Rates in Reaction Centers from Rhodobacter sphaeroides.
Influence of Hydrogen Bonds on the Electron-Phonon Coupling Strength/Marker Mode Structure and Charge Separation Rates in Reaction Centers from Rhodobacter sphaeroides.
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DOI：
10.1021/acs.jpcb.9b08388
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
A. Khmelnitskiy;Joann C. Williams;James P. Allen;R. Jankowiak
中科院分区：
文献类型：
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作者：
A. Khmelnitskiy;Joann C. Williams;James P. Allen;R. Jankowiak
本文报道了球形红细菌L131 LH + M160 LH + M197 FH三氢键突变株的低温持续和瞬态烧孔（HB）光谱。这些光谱暴露了P-、B-和H-带的异质性，与电子转移（ET）时间和激发能量转移（EET）速率的分布一致。瞬态P+QA-空穴被观察到快速（几十ps或更快）的ET时间，并揭示了强耦合的声子和标记模式（S），而持久的空穴漂白的一小部分反应中心（RC）与长寿命的激发态的特征在于弱得多的电子-声子耦合。电子-声子耦合强度的暴露差异以及与标记模式的不同耦合似乎影响ET时间。共振和非共振燃烧持久HB光谱显示弱蓝（~150 cm-1）和大，红移（~300 cm-1）的P带的反空穴。较慢的EET时间从H-和B-带的特殊对二聚体提供了新的见解突变引起的异质性的氢键的影响。
Low-temperature persistent and transient hole-burning (HB) spectra are presented for the triple hydrogen-bonded L131LH+M160LH+M197FH mutant of Rhodobacter sphaeroides. These spectra expose the heterogeneous nature of the P-, B-, and H-bands, consistent with a distribution of electron transfer (ET) times and excitation energy transfer (EET) rates. Transient P+QA- holes are observed for fast (tens of ps or faster) ET times and reveal strong coupling to phonons and marker mode(s), while the persistent holes are bleached in a fraction of reaction centers (RCs) with long-lived excited states characterized by much weaker electron-phonon coupling. Exposed differences in electron-phonon coupling strength, as well as a different coupling to the marker mode(s) appear to affect the ET times. Both resonantly and nonresonantly burned persistent HB spectra show weak blue- (~150 cm-1) and large, red-shifted (~300 cm-1) anti-holes of the P band. Slower EET times from the H- and B-bands to the special pair dimer provide new insight on the influence of hydrogen bonds on mutation-induced heterogeneity.