Department of Biochemistry, University of Massachusetts.
Proc Natl Acad Sci U S A. 1982 Nov;79(21):6532-6. doi: 10.1073/pnas.79.21.6532.
Photochemical activity was examined in membrane fragments and a purified membrane preparation from Chloroflexus. Flash-induced absorption difference spectroscopy strongly suggests a primary donor (P(865)) that is more similar to the P(870) bacteriochlorophyll a dimer found in the purple photosynthetic bacteria than it is to P(840) found in the anaerobic green bacteria. Redox measurements on P(865) and an early acceptor also indicate a photochemical system characteristic of the purple bacteria. The membrane preparation contains a tightly bound type c cytochrome, c(554), that is closely coupled to the reaction center as indicated by its ability to rereduce photooxidized P(865). Chloroflexus thus appears to be distinct photochemically from other families of photosynthetic bacteria and may occupy an important role in photosynthetic evolution.
光化学活性在 Chloroflexus 的膜片段和纯化的膜制剂中进行了研究。闪光诱导吸收差光谱强烈表明存在一个主要供体 (P(865))，它与在紫色光合细菌中发现的 P(870)细菌叶绿素 a 二聚体更相似，而不是在厌氧绿色细菌中发现的 P(840)。对 P(865)和早期受体的氧化还原测量也表明，该光化学系统具有紫色细菌的特征。膜制剂含有一种紧密结合的 c 型细胞色素 c(554)，它与反应中心紧密偶联，这表明它能够将光氧化的 P(865)还原。因此，Chloroflexus 在光化学上与其他光合细菌家族明显不同，可能在光合作用进化中占据重要地位。
