Department of Biochemistry, University of Cambridge, Tennis Court Road, CB2 1QW, Cambridge, UK.
Photosynth Res. 1985 Dec;6(4):335-48. doi: 10.1007/BF00054107.
The mechanisms by which para-benzoquinols can be oxidized is reviewed. Emphasis is placed on the information available from chemical and electrochemical studies which may provide insight into the biochemical mechanisms of plastoquinol oxidation in the chloroplast. Three mechanisms of quinol oxidation are possible: (1) The removal of an electron from the quinol, QH inf2 (sup·t) , directly to produce the radical cation, QH 2 (·+) . This may be achieved electrochemically only at very high potential in acidic media. The reaction may be of relevance to D1, the donor to P-680. (2) The removal of an electron from the anionic quinol. QH(-), formed by quinol deprotonation. It is likely that the catalytic mechanism of the cytochrome bf complex involves this mechanism. (3) The removal of an electron from the dianionic quinol, Q(2-). This route will be dominant only under basic or aprotic conditions and at very low potentials.
醌醇被氧化的机制得到了综述。重点介绍了来自化学和电化学研究的信息，这些信息可能有助于深入了解叶绿体中质体醌醇氧化的生化机制。醌醇氧化有三种可能的机制：（1）将电子从醌醇 QH inf2（上标·t）直接转移到自由基阳离子 QH 2（上标·+）上，从而去除电子。这只能在酸性介质中非常高的电势下通过电化学方法实现。该反应可能与 D1（P-680 的供体）有关。（2）从去质子化形成的阴离子醌醇 QH(-)上除去电子。细胞色素 bf 复合物的催化机制可能涉及这种机制。（3）从二价醌醇 Q(2-)上除去电子。只有在碱性或非质子性条件下和非常低的电位下，这种途径才占主导地位。
