温度对PSⅡCP4 7/D1/D2/Cytb559复合物荧光光谱特性的影响

采用激励光源为514.5 nm的分幅扫描单光子计数荧光光谱装置对经20℃、42℃和48℃不同温度处理后的反应中心复合物CP47/D₁/D₂/Cyt b559的荧光光谱特性进行了研究.经解析,获得不同温度处理后,CP47/D₁/D₂/Cyt b559复合物最大峰值未发生变化,均在682 nm,说明Chla670的能量都由Chla682接收,但损耗愈来愈小,在48℃时,损耗程度最小,而其荧光百分比未发生多大变化.振动副带～700 nm和～740 nm的中心波长都发生蓝移,在不同温度下分别为:20℃ 703 nm,749 nm;42℃ 697 nm,744 nm;48℃ 694 nm,740 nm.因此可以推测温度的升高,影响了CP47/D₁/D₂/Cyt b559色素蛋白的二级结构以及色素分子的空间位置,使最大峰值处的荧光强度逐渐降低,振动副带逐渐蓝移.42℃的温度已造成影响,48℃影响较大.

Effect of Temperature on the Fluorescence Spectrum Characteristics of the PSⅡ Reaction Center CP47/D1/D2/Cyt b559 Complex

Effect of temperature on the fluorescence spectrum characteristics of the PSⅡ reaction center CP47/D₁/D₂/Cyt b559 complex was studied by the framing scanning single photon counting spectrum setup. The CP47/D₁/D₂/Cyt b559 complex were treated at 20℃,42℃ and 48℃ respectively. Their fluorescence emission spectra were gained. By resolving, the fluorescence spectra showed the relative fluorescence intensity of maximum peak ～682 nm decreased with temperature ascending: 20℃ 190; 42℃ 177; 48℃ 141; vibrational sub-bands at ～700 nm and ～740 nm occurred blue shift with the temperature ascending: 20℃ 704 nm, 749 nm;42℃ 697 nm,744 nm;48℃ 694 nm,740 nm. Therefore, the change of protein conformation and spatial orientation of the CP47/D₁/D₂/Cyt b559 complex caused by temperature ascending influenced the fluorescence spectrum characteristics. There were more obvious changes at 42℃ and the most obvious changes at 48℃.