Zhang Haibo, Chobot Sarah E, Osyczka Artur, Wraight Colin A, Dutton P Leslie, Moser Christopher C
Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA.
J Bioenerg Biomembr. 2008 Oct;40(5):493-9. doi: 10.1007/s10863-008-9174-6. Epub 2008 Oct 31.
The Q cycle mechanism proposed by Peter Mitchell in the 1970's explicitly considered the modification of ubiquinone two-electron redox properties upon binding to Complex III to match the thermodynamics of the other single-electron redox cofactors in the complex, and guide electron transfer to support the generation of a proton electro-chemical gradient across native membranes. A better understanding of the engineering of Complex III is coming from a now moderately well defined thermodynamic description of the redox components as a function of pH, including the Qi/heme b(H) cluster. The redox properties of the most obscure component, Qo, is finally beginning to be resolved.
彼得·米切尔在20世纪70年代提出的Q循环机制明确考虑了泛醌在与复合体III结合时双电子氧化还原特性的改变，以匹配该复合体中其他单电子氧化还原辅因子的热力学性质，并引导电子传递以支持跨天然膜的质子电化学梯度的产生。对复合体III工程的更好理解来自于目前对氧化还原成分作为pH函数的适度明确的热力学描述，包括Qi/血红素b(H)簇。最模糊的成分Qo的氧化还原特性终于开始得到解决。
