摘要
利用ICCD皮秒、飞秒扫描成像和飞秒时间分辨光谱装置实验研究了高等植物捕光天线LHCⅡ三聚体和PSⅡ颗粒复合物及PSⅡ核心复合物的超快光谱动力学,经过吸收光谱和发射光谱分析,确定在LHCⅡ三聚体中至少存在7种Chl分子光谱特性,它们是:Chlb653/656658.7、Chla662。0665。2、Chla/b670/671671.6、Chla675.0677.1、Chla680/681682.9、Chla685689.1和Chla695.0695.6。采用光强103光子/cm2/脉冲激励浓度为30μg/ml的捕光天线LHCⅡ三聚体,在650nm到705nm谱段逐点探测分析处理,产生了两组短寿命组分210fs、520fs和5.2ps、36.7ps及两个长寿命组分1.8ns、2ns。最快的三个寿命210fs、520fs和5.2ps反映了三聚体Chlb分子向Chla分子的激发能传递过程;寿命36.7ps反映了Chla分子向相邻单体Chla分子的激发能传递过程;最长的两个寿命1.8ns和2ns是在三聚体中Chla分子通过中间体Chla分子辐射荧光,分别跃迁回基态的过程。获得的六个寿命组分有把激发能传递时间与Chla/b分子发射光谱相结合的特点。经拟合处理解析PSⅡ颗粒复合物光谱,得到三个组分谱,其峰值分别为686.8nm、692.2nm和694.9nm,与LHCⅡ比较分析,说明天然构型的PSⅡ有很强的吸收光能和有效传递光能的本领、PSⅡ核心复合物的核心天线CP43和CP47。
Ultrafast spectroscopy in the light-harvesting complex II, photosystem II particle complex and photosytem II core complex has been studied using ICCD femtosecond image scanning set and femtosecond time resolved spectrometer. 7 spectral components of chlorophyll a/b molecule have been obtained from the trimeric light-harvesting complex II, and they areChl b653/656658.7、Chl a662.0665.2、Chl a/b670/671671.6、Chl a675.0677.1、Chl a680/681682.9、Chl a685.0689.1 and Chla695.0695.6(Chl aae, a is the absorption spectrum peak, e is the emission spectrum peak). Exciting in the trimeric light-harvesting complex at 440 nm with intensity of 1013 photos/cm2/pulse, fluorescence kinetics from 605 nm to 705 nm, yields 4 ultrafast component lifetimes of 210 fs and 520 fs, 5.2 ps and 36.7 ps, and 2 long component lifetimes of 1.8 ns and 2 ns. The three fastest lifetimes of 210 fs , 520 fs and 5.2 ps directly reflect from trimeric Chl b to Chl a energy transfer processes. The lifetime 36.7 ps shows the energy transfer time from Chl a to nearby monomer Chl a. The longest 2 lifetimes reflect the energy transfer processes of Chl a molecules from excited state to ground state through middle Chl a molecules in the trimeric. CP43 and CP47 of PSII core antenna has three Chl a molecules of different condition, they are CP43-Chl a660661, CP43-Chl a669670, CP43-Chl a682686, CP47-Chl a660661, CP47-Chl a669670, CP47-Chl a680681
出处
《量子电子学报》
CAS
CSCD
北大核心
2002年第5期404-409,共6页
Chinese Journal of Quantum Electronics
基金
国家重点基础研究专项基金资助项目(编号:G1998010100)
