摘要
采用时间分辨荧光光谱技术研究了菠菜 (SpinaciaoleraceaL .)叶绿体中捕光色素复合体 (LHCⅡ )荧光的时间特性和光谱特性。用脉宽为 12 0fs、波长为 40 0nm的倍频钛宝石激光激发LHCⅡ样品 ;原始荧光信号由Boxcar采集 ,通过建立多指数模型 ,用非线性最小二乘法拟合 ,得到了激发能在LHCⅡ中传递的时间常数分别为 :32 0fs、4.0ps和 2 0 .0ps。相对应的各组分荧光占总荧光的百分比分别为 :3.4%、5 0 .0 %和 46 .6 %。经全局分析 ,解得荧光强度随波长变化曲线 ;用高斯 3峰解叠得到荧光光谱的峰值波长分别为 :6 5 2nm、6 72nm和 6 91nm。通过分析得出了时间常数与LHCⅡ中各色素成分之间的对应关系 。
Fluorescence properties of light-harvesting complex (LHCⅡ) in photosystem Ⅱ isolated from spinach (Spinacia oleraceaL.) was investigated with the time-resolved fluorescence spectroscopic technique. The sample was excited by double frequency Ti:Al 2O 3 laser with 400 nm wavelength and 120 fs width. Fluorescence signal was detected by Boxcar. Three life-time components (320 fs,4.0 ps and 20.0 ps) were obtained by multi-exponential curve model and nonlinear least-square fitting method. Three fluorescence peaks (652 nm, 672 nm, 691 nm) were obtained by Global analysis and Gauss curve fitting. These components were analyzed according to the structural and fluorescence spectroscopic property of LHCⅡ. The fluorescence ratio of each component to that of all the component was 3.4%, 50% and 46.6% respectively. The possible model of energy transfer in LHCⅡ was discussed.
基金
国家重点基础研究发展规划项目 (G19980 10 10 0 )~~
