Photochemical hole-burned spectra of protonated and deuterated reaction centers of Rhodobacter sphaeroides
Photochemical hole-burned spectra of protonated and deuterated reaction centers of Rhodobacter sphaeroides
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球形红杆菌质子化和氘化反应中心的光化学烧孔光谱
DOI：
10.1021/j100128a030
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
G. Small
中科院分区：
文献类型：
--
作者：
P. Lyle;S. Kolaczkowski;G. Small
光化学hole-burned光谱与提高信噪比([*]20)报告使质子化和氘反应中心的紫色细菌Rhodobacter sphaeroides。作为燃烧频率（[omega][下标B]）函数的光谱表明，在P870零声子线跃迁频率的非均匀分布中，主电子给态P870*的寿命与[omega][下标B]的位置是不变的。对于质子化和氘化的RC，其在4.2 K下的P870吸收宽度仅为440和420 cm[sup [minus]1]，零声子空穴的寿命为0.93 [+-]0.10 ps。该寿命与1.6至8.0 K（可以研究零声子空穴的范围）之间的温度无关。P870*寿命对[omega][sub B]等数据的不变性表明P870* （Vos等）的非指数衰减。Proc。国家的。学会科学。美国1991,88,8885)既不是由于与电子转移相关的电子耦合矩阵元素的值分布，也不是由于RC的普通玻璃状结构非均质性。更高质量的孔光谱允许对先前用于模拟更多»P870孔轮廓和吸收光谱的理论模型进行更严格的测试。虽然早期报告的基本发现（例如，见Reddy等人）。Photosyn。Res. 1992, 31,167)没有改变，因此可以得出结论，低频声子（平均频率约为30 cm[sup[-]1]）的分布模型，其耦合到P870*，在Debye分布方面是不充分的。玻璃和聚合物的反常低频模式对蛋白质也很重要。参60。， 8个无花果。， 2个标签。«少
Photochemical hole-burned spectra with improved signal-to-noise ratio ([times]20) are reported for the protonated and deuterated reaction center of the purple bacterium Rhodobacter sphaeroides. Spectra obtained as a function of burn frequency ([omega][sub B]) establish that the lifetime of P870*, the primary electron-donor state, is invariant to location of [omega][sub B] within the inhomogeneous distribution of P870 zero-phonon line transition frequencies. For both the protonated and deuterated RC, which exhibit P870 absorption widths at 4.2 K of only 440 and 420 cm[sup [minus]1], the zero-phonon holes yield a lifetime of 0.93 [+-] 0.10 ps. This lifetime is independent of temperature between 1.6 and 8.0 K (range over which the zero-phonon hole could be studied). The invariance of the P870* lifetime to [omega][sub B] and other data indicates that the nonexponential decay of P870* (Vos et al. Proc. Natl. Acad. Sci. U.S.A. 1991, 88, 8885) is due neither to a distribution of values from the electronic coupling matrix element associated with electron transfer, which one might expect from the normal glasslike structural heterogeneity of the RC, nor to gross heterogeneity. The higher quality of the hole spectra has allowed for more stringent testing of the theoretical model previously used to simulate themore » P870 hole profiles and absorption spectrum. Although the essential findings reported earlier (see, e.g., Reddy et al. Photosyn. Res. 1992, 31, 167) are not altered, it is concluded that the modeling of the distribution of low-frequency phonons (mean frequency approximately 30 cm[sup [minus]1]), which couples to P870*, in terms of a Debye distribution is inadequate. The anomalous low-frequency modes of glasses and polymers are suggested to be important also for proteins. 60 refs., 8 figs., 2 tabs.« less