Biochemistry Department, Weizmann Institute of Science, 76100, Rehovot, Israel.
Photosynth Res. 1986 Jan;10(3):405-13. doi: 10.1007/BF00118306.
Energy dependent reverse electron flow reactions in isolated thylakoids provide a unique tool to study, in the dark, the coupling between the ATP synthase, proton transport and the electron transfer system. Appropriate experimental conditions have been established to follow experimentally the following reactions: 1. ATP driven proton uptake into the inner-thylakoid space, which requires preactivation of the ATP synthase. 2. ATP driven reverse electron transport, which involves proton transport as an intermediate, and results in the reduction of QA by an externally added electron donor. 3. ATP driven luminescence, which requires the presence of an oxidized partner on the water side of photosystem II, and involves electron transport from QB to QA. 4. ΔpH driven reverse electron flow, which does not require the participation of the ATP synthase, and uses reduced intermediates between the two photosystems as electron donors for the reduction of QA. 5. ΔpH driven luminescence which again uses reduced intermdiates between the two photosystems as electron donors for QA reduction, and requires the presence of an oxidized partner on the water side of photosystem II. Several of these reactions have been shown to occur in intact chloroplasts and may provide an important regulatory mechanism in vivo.
在分离的类囊体中，能量依赖的反向电子流反应为研究 ATP 合酶、质子转运和电子传递系统之间的偶联提供了一种独特的工具。已经建立了适当的实验条件来实验性地跟踪以下反应：1. ATP 驱动的质子内吞进入类囊体腔，这需要 ATP 合酶的预激活。2. ATP 驱动的反向电子传递，其中质子转运作为中间体，导致外部添加的电子供体还原 QA。3. ATP 驱动的发光，这需要 PSII 水侧存在氧化伴侣，并涉及从 QB 到 QA 的电子传递。4. ΔpH 驱动的反向电子流，不需要 ATP 合酶的参与，并且使用两个光系统之间的还原中间体作为电子供体来还原 QA。5. ΔpH 驱动的发光，再次使用两个光系统之间的还原中间体作为电子供体来还原 QA，并且需要 PSII 水侧存在氧化伴侣。其中一些反应已在完整的叶绿体中显示出发生，并且可能在体内提供了一种重要的调节机制。
