毕氏海蓬子光系统Ⅱ颗粒的分离与鉴定

采用去污剂TritonX-100增溶类囊体膜和高速离心的方法，首次分离和纯化了毕氏海蓬子的光系统Ⅱ（photosystemⅡ，PSⅡ）颗粒，通过光谱学和SDS-PAGE对其进行鉴定并与类囊体膜进行比较。室温吸收光谱结果表明，PSⅡ颗粒在蓝区的叶绿素（chlorophyll，ChOb和胡萝卜素类吸收峰为485nm，在红区的Ch1b吸收峰为655nm，这两个峰值均低于类囊体膜中的。77K荧光发射光谱结果表明，提取的PSⅡ颗粒基本不含光系统Ⅰ（photosystemⅠ，PSI）的低温荧光反射峰737nm。77K荧光激发光谱结果显示，海蓬子PSⅡ颗粒在470-485am之间的Ch1b 和胡萝卜素类的荧光发射峰明显低于类囊体膜的。这说明在PSⅡ中大部分的PSI已被除去。电泳结果显示，海蓬子PSⅡ颗粒缺少PSI反应中心蛋白质亚基PsaA和PsaB，这说明提取到的PSⅡ纯度较高，这为进一步研究毕氏海蓬子PSⅡ的结构与功能奠定基础。

Isolation and Identification of Photosystem II Protein of Salicornia bigelovii Torr.

The photosystem Ⅱ （PSⅡ） of Salicornia bigelovii from coastal wetlands was firstly isolated and purified by solubilization of thylakoid liaembrane using detergent Triton X-100 and high-speed centrifugation. The PSⅡ particles of S. bigelovii were studied and compared with thylakoid membrane by spectroscopy and SDS-PAGE methods. The results of absorption spectra at room temperature showed that the absorption peak of chlorophyll （Ch1） b and carotenoid in the blue region was 485 nm, and the absorption peak of Chl b in the red region was 655 nm. Moreover, the two peaks were lower than those in the thylakoid membrane. The results of 77K fluorescence emission spectra showed that PSⅡ particles extracted were free of the low temperature fluorescence peak 737 nm of photosystem Ⅱ（PSI）. It was shown from 77K fluorescence excitation spectra that the emission peak between 470-485 nm was lower than that of the thylakoid membrane. These indicated that most of the PSI has been removed from the extracted PSⅡ. The PSⅡ particles of S. bigelovii were lack of PSI reaction center protein subunits （PsaA and PsaB）. It demonstrated that the extracted PSⅡ particles were high purity, which could be used for further study on the structure and function ofS. bigelovii.