紫细菌RS601 DCPIPH_2→MV电子传递的研究  

The Characteristics of DCPIPH_2→MV Electron Transport in Rb. sphaeroides 601

作　　者：曾小华[1] 俞皓[2] 吴永强 吴梦淦 魏家绵 宋鸿遇 徐春和 

机构地区：[1]中国科学院上海植物生理研究所,200032 [2]上海交通大学生物科学与技术系,200030

出　　处：《生物化学与生物物理学报》1997年第1期46-52,共7页

基　　金：国家自然科学基金(39370007)资助项目

摘　　要：紫色非硫细菌菌株Rb.sphaeroides 601(RS601)的载色体具有典型的Rb.spkaeroides光谱特性。在光照和以DCPIPH_2为电子供体条件下,RS601载色体能够串联呼吸电子传递链而耗氧或还原MV而构成DCPIPH_2→MV的非循环电子传递链。电子传递抑制剂OP抑制DCPIPH_2→MV电子传递活性,其I_(50)为1.0 mmol/L;抗霉素A对该电子传递影响较小,不存在I_(50)。因此,MV在RS601中被还原的部位应介于次级醌双电子受体Q_B和细胞色素b之间,而不应在Q_A位置。讨论了Rb.sphaeroides与Rs.rubrum反应中心还原侧电子传递特性的差异。MV接受电子的位置可能因光细菌的品系的不同而不同。The absorption spectrum and fluorescence emission spectrum of RS601 were found to keep the typical characteristics of those of the purple nonsulfide bacteria Rb. sphaeroides. Under illumination, methyl viologen was reduced by RS601 chromatophores in the presence of DCPIPH_2 as the electron donor, setting up a standard noncyclic electron transport, o-phenanthroline with I_(50) of 1.0 mM inhibited the DCPIPH_2→MV electron transport. Antimycin A did not inhibit the DCPIPH_2→MV electron transport and had no I_(50). The results suggested that the exact site where methyl viologen accepted electron should locate between the secondary electron acceptor, Q_B, and cyt b, but not at the Q_A binding site as indicated before. The difference of electron transport between reduced sides of reaction centers of Rb. sphaeroides and Rs. rubrum was discussed.

关 键 词：紫细菌 载色体 DCPIPH2 MV 电子传递 光合作用 

分 类 号：Q939.107[生物学—微生物学] Q945.11