SECOND-SPHERE TUNING OF THE METAL ION REDUCTION POTENTIALS IN IRON AND MANGANESE SUPEROXIDE DISMUTASES
SECOND-SPHERE TUNING OF THE METAL ION REDUCTION POTENTIALS IN IRON AND MANGANESE SUPEROXIDE DISMUTASES
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DOI：
10.1080/02603590802429529
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发表时间：
2008-01-01
影响因子：
5.4
通讯作者：
Brunold, Thomas C.
中科院分区：
文献类型：
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作者：
Grove, Laurie E.;Brunold, Thomas C.
铁和锰超氧化物歧化酶（分别为Fe-和MnSOD）是催化超氧化物分解为分子氧和过氧化氢的金属酶，由此金属离子在氧化态和单电子还原态之间循环。虽然铁和MnSOD表现出类似的蛋白质和活性位点的结构，它们显示严格的金属离子特异性。为了理解这种特异性的起源，我们进行了光谱和计算研究的各种FeSOD物种，发现某些第二球残基施加显着的控制质子耦合金属离子的还原电位，这必须调整不同的活性位点结合的铁和锰，以允许基板的氧化和还原。
Iron and manganese superoxide dismutases (Fe- and MnSODs, respectively) are metalloenzymes that catalyze the disproportionation of superoxide to dioxygen and hydrogen peroxide whereby the metal ion cycles between an oxidized and one-electron reduced state. Although Fe- and MnSODs exhibit similar protein and active-site structures, they display strict metal-ion specificities. To understand the origin of this specificity, we performed spectroscopic and computational studies of various FeSOD species and found that certain second-sphere residues exert significant control over the proton-coupled metal ion reduction potential, which must be tuned differently for active site-bound Fe and Mn to permit both substrate oxidation and reduction.