A new fluorescence band F689 in photosystem II revealed by picosecond analysis at 4-77 K: Function of two terminal energy sinks F689 and F695 in PSII
A new fluorescence band F689 in photosystem II revealed by picosecond analysis at 4-77 K: Function of two terminal energy sinks F689 and F695 in PSII
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DOI：
10.1016/j.bbabio.2006.09.007
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发表时间：
2006-12-01
影响因子：
4.3
通讯作者：
Itoh, Shigeru
中科院分区：
文献类型：
--
作者：
Komura, Masayuki;Shibata, Yutaka;Itoh, Shigeru
我们对菠菜光系统II （PS II）颗粒在4、40和77 K下进行皮秒时间分辨荧光光谱分析，发现了一个新的荧光带F689。在衰减相关光谱和时间分辨光谱的全局高斯反褶积分析中，除F685和F695外，还发现了F689。它的快速衰减表明能量直接从F689转移到反应中心叶绿素P680。F689的贡献仅在低温下增加，这解释了F695在低温下异常宽和可变的带宽。全局分析结果表明：(1)外围天线向F685、F689和F695三个核心天线频段的能量转移，在77 K和4 K时的时间常数分别为29和171 ps；(2)三个芯带之间（0.18 ~ 0.82 ns）；F689和F695的衰减分别为0.69和3.02 ns和2.18和4.37 ns。这些能量转移速率的延迟和F689缓慢的衰变速率导致PS II荧光在冷却至77 K以下时出现强烈的蓝移。(c) 2006 Elsevier B.V.版权所有
We performed picosecond time-resolved fluorescence spectroscopy in spinach photosystem II (PS II) particles at 4, 40, and 77 K and identified a new fluorescence band, F689. F689 was identified in addition to the well-known F685 and F695 bands in both analyses of decay-associated spectra and global Gaussian deconvolution of time-resolved spectra. Its fast decay suggests the energy transfer directly from F689 to the reaction center chlorophyll P680. The contribution of F689, which increases only at low temperature, explains the unusually broad and variable bandwidth of F695 at low temperature. Global analysis revealed the three types of excitation energy transfer/dissipation processes: (1) energy transfer from the peripheral antenna to the three core antenna bands F685, F689, and F695 with time constants of 29 and 171 ps at 77 and 4 K, respectively; (2) between the three core bands (0.18 and 0.82 ns); and (3) the decays of F689 (0.69 and 3.02 ns) and F695 (2.18 and 4.37 ns). The retardations of these energy transfer rates and the slow F689 decay rate produced the strong blue shift of the PS II fluorescence upon the cooling below 77 K. (c) 2006 Elsevier B.V. All rights reserved.