Poole Leslie B
Department of Biochemistry, Center for Structural Biology, BGTC, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
Subcell Biochem. 2007;44:61-81. doi: 10.1007/978-1-4020-6051-9_4.
Peroxiredoxins carry out the efficient reduction of a typically broad range of peroxide substrates through an absolutely conserved, activated cysteine residue within a highly conserved active site pocket structure. Though details of reductive recycling after cysteine sulfenic acid formation at the active site vary among members of different Prx classes, local unfolding around the active site cysteine is likely generally required in these proteins for disulfide bond formation with a second resolving cysteine and/or for access of the reductant to the oxidized active site. The conformational change associated with the catalytic cycle and the redox-dependent decamer formation occurring in at least some typical 2-Cys Prxs have interesting implications in the interplay between active site loop dynamics, oligomerization state, catalytic efficiency and propensity toward inactivation during turnover in these important antioxidant enzymes.
过氧化物酶通过位于高度保守的活性位点口袋结构内的一个绝对保守的活化半胱氨酸残基，对一系列典型的过氧化物底物进行高效还原。尽管不同过氧化物酶家族成员在活性位点形成半胱氨酸亚磺酸后还原循环的细节有所不同，但这些蛋白质通常可能需要活性位点半胱氨酸周围发生局部去折叠，以便与第二个解离半胱氨酸形成二硫键和/或使还原剂接近氧化的活性位点。与催化循环相关的构象变化以及至少在一些典型的2-半胱氨酸过氧化物酶中发生的氧化还原依赖性十聚体形成，对于这些重要抗氧化酶在周转过程中活性位点环动态、寡聚化状态、催化效率和失活倾向之间的相互作用具有有趣的影响。
