Plant Biochemistry Laboratory, Department of Plant Biology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Copenhagen, Denmark.
Photosynth Res. 1994 Jul;41(1):105-14. doi: 10.1007/BF02184150.
The photosynthetic reaction center complex from the green sulfur bacteriumChlorobium vibrioforme has been isolated under anaerobic conditions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveals polypeptides with apparent molecular masses of 80, 40, 30, 18, 15, and 9 kDa. The 80- and 18-kDa polypeptides are identified as the reaction center polypeptide and the secondary donor cytochromec 551 encoded by thepscA andpscC genes, respectively. N-terminal amino acid sequences identify the 40-kDa polypeptide as the bacteriochlorophylla-protein of the baseplate (the Fenna-Matthews-Olson protein) and the 30-kDa polypeptide as the putative 2[4Fe-4S] protein encoded bypscB. Electron paramagnetic resonance (EPR) analysis shows the presence of an iron-sulfur cluster which is irreversibly photoreduced at 9K. Photoaccumulation at higher temperature shows the presence of an additional photoreduced cluster. The EPR spectra of the two iron-sulfur clusters resemble those of FA and FB of Photosystem I, but also show significantly differentg-values, lineshapes, and temperature and power dependencies. We suggest that the two centers are designated Center I (with calculatedg-values of 2.085, 1.898, 1.841), and Center II (with calculatedg-values of 2.083, 1.941, 1.878). The data suggest that Centers I and II are bound to thepscB polypeptide.
从绿硫细菌（Chlorobium vibrioforme）中分离出了光合反应中心复合物，在无氧条件下进行。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示出表观分子量为 80、40、30、18、15 和 9 kDa 的多肽。80 和 18 kDa 的多肽分别被鉴定为反应中心多肽和由 pscA 和 pscC 基因编码的次级供体细胞色素 c 551。N 端氨基酸序列鉴定出 40 kDa 的多肽为基片上的细菌叶绿素 a 蛋白（Fenna-Matthews-Olson 蛋白），30 kDa 的多肽为 pscB 编码的假定 2[4Fe-4S]蛋白。电子顺磁共振（EPR）分析表明存在一个铁硫簇，在 9K 时不可逆地被光还原。在较高温度下的光积累表明存在另外一个被光还原的簇。两个铁硫簇的 EPR 谱类似于光系统 I 的 FA 和 FB，但也显示出明显不同的 g 值、线宽和温度和功率依赖性。我们建议将这两个中心分别命名为中心 I（计算出的 g 值为 2.085、1.898、1.841）和中心 II（计算出的 g 值为 2.083、1.941、1.878）。数据表明，中心 I 和 II 与 pscB 多肽结合。
