光系统Ⅱ核心天线的低温荧光光谱及动力学研究(英文)  

Low-Temperature Fluorescence Spectroscopy and Kinetics in the Photosystem Ⅱ Core Complex

作　　者：蔡霞[1] 王水才[2] 贺俊芳[2] 刘晓[1] 彭菊芳[3] 

机构地区：[1]西北大学生命科学学院,西安710069 [2]中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室,西安710119 [3]陕西师范大学生命科学学院,西安710061

出　　处：《光子学报》2008年第7期1441-1445,共5页Acta Photonica Sinica

基　　金：Supported by the State Key Research and Development Plan of China(G1998010100)

摘　　要：采用稳态及飞秒荧光光谱技术研究了光系统Ⅱ中核心复合物在83K、160K和273K低温下的能量传递途径.激发波长为507nm.随着温度的升高,稳态荧光光谱逐渐发生蓝移.通过对不同温度下稳态光谱进行高斯解析,获得5个特征叶绿素a分子,分别为Chla 670670.4,Chla680681.9,Chla683683.9,Chla687687.5687.8689和Chla690698.0,其中仅有Chla687687.5687.8.689在3个温度下的光谱中都解析获得,并且其谱宽以及荧光比例都随着温度升高而增加,因此推断温度对CP47中易裂解的叶绿素a分子有较大的影响.在680nm以及690nm波长处对不同温度下的时间曲线利用F900时间处理系统进行拟合,获得73ps、110ps、186ps、246～972ps和1～3.7ns5个时间组分。其中,73ps是电荷分离的时间;110ps和186ps是β-Car分子受激发后,将激发能最终传递给反应中心所需要的时间;246～972ps是电荷重组的时间过程;而1～3.7ns是激发态分子发生电荷重组后又衰退回到基态的时间.73ps的时间组分只在83K温度下得到,因此,随着温度降低,可以探测到快的时间组分.此外,对光谱随温度升高而发生蓝移进行了分析.Low-temperature fluorescence spectroscopy and kinetics in the core complex of photosystem Ⅱ were studied with the methods of steady state and femtosecond fluorescence spectra techniques. The spectra at 83 K, 160 K and 273 K show the maximum becomes blueshifted from 693.0 nm at 83 K to 683.0 nm at 160 K, and it is almost no shift at above 160 K. And the shoulder at long wavelength region becomes less apparent as the temperature increasing. Five groups of Chlorophyll a molecules marked as Chl a670^670.4, Chl a680^681.9, Chl a683^683.9, Chl a687^687.5,687.8.689, Chl a690^698.0 were discovered from spectra at three temperatures, Based on the analyses of decay kinetics, five lifetime components were obtained to be 73 ps, 110ps, 186 ps, 246-972 psand 1-3.7 ns. With the decreasing of temperature, the faster time component can be detected. In addition, the blueshift of the spectrum was discussed.

关 键 词：光生物学 荧光光谱学 荧光动力学 光系统Ⅱ中核心复合物 

分 类 号：Q631[生物学—生物物理学]