【摘要】 菠菜叶绿体光系统Ⅱ反应中心D1/D2/Cyt b-559复合物的荧光衰减包括4个组分,其寿命分别大约为1.0 ns、5.9 ns、24 ns和73 ns,所占整个荧光的量子产率依次为0.05,0.34,0.35和0.26。这些不同寿命组分的荧光发射光谱相互重叠在一起,稳态光谱只显示1个发射峰。根据相调荧光测定的"硬件"分析方法,通过选择检测器的相角,可以选择性地把各个寿命组分的荧光分别滤掉。如果5.9 ns组分的荧光被滤掉,发射光谱发生红移;相反,如果73 ns组分的荧光被滤掉,发射光谱则发生蓝移。根据"软件"分析方法,通过测定在各个波长处的调制光相角和调制数值.可以把不同寿命组分各自的荧光发射光谱分辨出来。与稳态荧光光谱相比,5.9 ns组分的最大发射波长发生蓝移,由682 nm移到680 nm;而24 ns和73 ns组分的最大发射波长发生红移,分别为685 nm和683 nm。更多还原

【Abstract】 PS Ⅱ reaction center D1/D2/Cyt b-559 purified from chloroplasts of spinach has four components of fluorescence decaying with lifetimes of 1. 0 ns,5. 9 ns,24 ns,and 73 ns whose fractions to total fluorescence yield are 0. 05, 0. 34,0. 35 and 0. 26 respectively. The fluorescence emission spectra of these lifetime components are closely overlapping, and only one peak is shown in steady state emission spectrum. Based on the hardware analysis of phase fluorometry ,by selection of the detector phase angle,the emission from various components could be individually suppressed. If the 5. 9 ns component was suppressed, the emission spectrum was red-shifted. On the contrary,the emission spectrum was blue-shifted when 73, ns component was suppressed. Based on the software analysis, the individual emission spectra were resolved with three lifetime components by measuring phase and modulation data at various wavelength. Compared with steady state spectrum, the emission maximum wavelength of 5. 9 ns component was blue-shifted from 682 nm to 680 nm,but those of 24 ns and 73 ns components were red-shifted to 685 nm and 683 nm respectively.更多还原