高等植物光系统Ⅱ反应中心的亚纳秒时间分辨荧光光谱的测量

高等植物光系统Ⅱ是光合作用中的一个非常重要的单元,它是与裂解水放氧相关的功能结构,光系统Ⅱ反应中心是进行光化学反应的场所,在其内部发生的光能的吸收、激发态的传递、电荷的分离重组以及迁移等等过程,都是在非常短的时间里发生的,其时间尺度在10^-15～10^-7s之间,本文建立了亚纳秒时间分辨荧光光谱测量装置,并对菠菜光系统Ⅱ反应中心蛋白复合体D₁/D₂/cyt b─559,在不同波长激发下的时间分辨荧光光谱进行了测量,经过解卷积和多指数数据拟合,获得4个寿命组分,并对结果进行了分析讨论,指出在不同的激发波长激发下的荧光衰减曲线的差异可能源于被激发的组分不同和能量传递路径的不同.

MEASUREMENT OF SUBNANOSECOND TIME─RESOLVED FLUORESCENCE SPECTRA OF PHOTOSYSTEM Ⅱ REACTION CENTER FROM HIGHER PLANTS

Photosystem Ⅱ of higher plants is an important unit in the photosynthesis,which is the functional structure associated with the process of water split and oxygen released.Photosystem reaction center is the site where the photo chemical reactions take place,which include ligh tabsorption,excitation transfer,charge separation,recombination and transport,etc.All of these primary photosynthetic reaction are involved in the ultrashort time scale ranging from 10^-15～10^-7s.In thisarticle,a very simple apparatus of measurement of subnanosecond time-resolved fluorescence spectra isrepresented.Using the apparatus,the time-resolved fluorescence spectra of ps,the reaction center from spinach is recorded at a series of wave length with different excitation wavelength.After decovolution and fitting of the experiment data,several life time of components is obtained.Some discussion and analysis of the measurement results are also available.