质体醌库和细胞色素b_6f参与调控蓝细菌Synechocystis sp.PCC 6803的状态转换  

PLASTOQUINONE POOL AND CYTOCHROME b_6f ARE INVOLVED IN STATE TRANSITIONS OF Synechocystis sp.PCC6803

作　　者：毛海滨[1] 李国富[1] 阮翔[1] 吴庆余[1] 公衍道[1] 张秀芳[1] 赵南明[1] 

机构地区：[1]清华大学生物科学与技术系生物膜与膜生物工程国家重点实验室,北京100084

出　　处：《生物物理学报》2002年第3期313-317,共5页Acta Biophysica Sinica

基　　金：国家重点基础研究发展规划项目(G1998010100); 国家自然科学基金重大项目(39890390)

摘　　要：用调制叶绿素荧光研究了对苯醌(1,4-benzoquinone,BQ)和二溴百里香醌(2,5-dibromo-3-methyl-6-isopropyl-1,4-benzoquinone,DBMIB)对蓝细菌Synechocystissp.PCC6803状态转换的作用。BQ和DBMIB是质体醌(PQ)的类似物,两者均可充当PQ的电子受体。其中,DBMIB能够和细胞色素b6f的Qo位点特异结合。在没有作用光的情况下,BQ诱导暗适应的蓝细菌进入状态Ⅰ;相反,DBMIB诱导Syne鄄chocystis6803向状态Ⅱ转换。据此提出,在生理状态下蓝细菌根据PQ库的氧化还原状态调节状态转换;细胞色素b6f参与此调控过程。The effects of 1,4-benzoquinone (BQ) and 2,5-dibromo-3-methy l- 6-isopropyl-p-benzoquinone (DBMIB) on the state transitions of Synechocyst is sp. PCC 6803 were investigated by using modulated chlorophyll fluores cence. Both BQ and DBMIB are benzoquinone analogues and can accept el ectrons from plastoquinone. DBMIB also can bind to the Qo site of th e cytochrome b 6 f complex with high affin-ity. In the absence of actinic light, B Q induced a transition from state 2 to state 1 in dark-adapted cells. To the contrary, DBMIB induced transition to state 2 in the presence of BQ or DCMU (3-(3',4'-dichlorophenyl)-1,1-dimethylurea). These results imply that the redox state of plastoquinone pool con-trols the state transitions and cytochrome b 6 f is involved in these processes.

关 键 词：质体醌库 细胞色素b6f 调控 蓝细菌 状态转换 叶绿素荧光 

分 类 号：Q945.11[生物学—植物学]