The Possible Mechanism of Photoinhibition of Purified PSⅠ Complexes  

PSⅠ颗粒光抑制的可能机理(英文)

作　　者：魏捷[1] 余辉 李良璧 匡廷云[1] 王居硕[2] 公衍道[2] 赵南明[2] 

机构地区：[1]中国科学院植物研究所光合作用基础研究开放实验室,北京100093 [2]清华大学生物科学与技术系,北京100084

出　　处：《Acta Botanica Sinica》2001年第1期18-23,共6页Acta Botanica Sinica（植物学报：英文版）

基　　金：SupportedbytheNationalNaturalScienceFoundationofChina ( 3 9890 3 90 ) ;StateBasicResearchandDevelopmentPlan (G19980 10 10 0 )an

摘　　要：The protecting effect of histidine on the photodamage of pigments and proteins of the isolated PSⅠ particles from the chloroplast of Spinacia oleracea L. during the strong illumination (2 300 μmol·m -2 ·s -1 ) was studied by spectroscopy and SDS_PAGE. The absorbance of PSⅠ particles decreased during the strong illumination treatment, but the decrease would be slowed down in the presence of externally added histidine after 30 min illumination. The decrease of CD (circular dichroism) signal intensities of PSⅠ particles also was slowed down by the added histidine after about 10 min illumination. The retarded protecting effect of the added histidine on the photobleaching of pigments of PSⅠ complexes implied that the mechanisms of photoinhibition of isolated PSⅠ complexes are different from early stage to later stage during the strong illumination treatment. In addition, the added histidine suppressed the decrease of 77 K fluorescence yield of PSⅠ particles during the illumination. SDS_PAGE showed that the added histidine not only protected the reaction center proteins of PSⅠ particles, but also protected other subunits of PSⅠ particles from degradation.从菠菜 (SpinaciaoleraceaL .)叶绿体中提取的PSⅠ颗粒中加入不同浓度的组氨酸 ,利用光谱和SDS_PAGE技术研究了强光 ( 2 30 0 μmol·m-2 ·s-1)处理过程中外加组氨酸对色素和多肽光破坏进程的影响。强光处理可以使PSⅠ颗粒的光吸收减小 ,在照光 30min后外加组氨酸有效地抑制了光吸收减小的趋势。外加组氨酸在照光约 10min后对PSⅠ颗粒CD信号的下降也起到了明显的抑制作用。外加组氨酸对PSⅠ颗粒中色素保护作用的这种延迟现象表明 ,在强光照初期和后期PSⅠ颗粒光抑制的机理可能不同。外加组氨酸还可以有效地抑制光照过程中PSⅠ颗粒 77K荧光产量的下降。SDS_PAGE分析结果发现 ,外加组氨酸在光照过程中不但对PSⅠ颗粒的反应中心蛋白可以起到保护作用 。

关 键 词：PSⅠ pigment_protein complex PHOTOINHIBITION HISTIDINE SPECTROSCOPY 

分 类 号：Q945.11[生物学—植物学]