Abstract An antioxidant enzyme inhibitor composed of polyethylene glycol-Cu,Zn superoxide dismutase and Mn catalase is proposed to eliminate peroxy radical ( OO ). The mechanism of the initial OO generation during coal self-oxidation was delineated. Three reactions were analyzed by quantum chemical. For the acylation reaction, the active sites of succinic acid and lysine have been identified through natural bond orbital and frontier molecular orbital analyses; pathways and mechanisms of the respective reactions have been proposed; the reaction involved two transition states and was associated with an activation energy (Ea) of 4.65 kJ/mol and an enthalpy change of −58.03 kJ/mol. For the disproportionation reaction between Cu,Zn-SOD and ROO , it was divided into four steps with an overall rate of 2.009 × 109 m −1 s−1; the first step was endothermic by 11.23 kJ/mol and needed to surmount an Ea of 31.3 kJ/mol; the second step was accompanied by a maximum heat release of 137.23 kJ/mol; the Cu2+ in the active center was reduced to Cu+ by consuming OO /H+, and then the Cu+ was oxidized to Cu2+ by again consuming OO . For the disproportionation reaction between Mn catalase and H2O2, it was divided into five steps with an overall rate of 3.267 × 106 m −1 s−1; the first and fourth steps were endothermic by 22.74 and 19.72 kJ/mol, respectively; for the fourth step, under the exothermic process, an Ea of 47.21 kJ/mol needed to be surmounted; the reaction mechanism involved mutual conversion between Mn(II) in the reduced state and Mn(III) in the oxidized state to consume hydrogen peroxide.

中文翻译：

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抗氧化酶抑制剂复合物消除过氧自由基的反应机理和热力学

摘要 提出了一种由聚乙二醇铜、锌超氧化物歧化酶和锰过氧化氢酶组成的抗氧化酶抑制剂来消除过氧自由基（OO）。描绘了煤自氧化过程中初始 OO 生成的机制。通过量子化学分析了三个反应。对于酰化反应，通过自然键轨道和前沿分子轨道分析确定了琥珀酸和赖氨酸的活性位点；提出了各自反应的途径和机制；该反应涉及两个过渡态，活化能 (Ea) 为 4.65 kJ/mol，焓变为 -58.03 kJ/mol。Cu,Zn-SOD与ROO的歧化反应分为四步，总速率为2.009×109 m -1 s-1；第一步是吸热 11.23 kJ/mol，需要超过 31.3 kJ/mol 的 Ea；第二步伴随着137.23 kJ/mol的最大放热；活性中心的Cu2+通过消耗OO/H+被还原为Cu+，然后通过再次消耗OO将Cu+氧化为Cu2+。Mn过氧化氢酶与H2O2的歧化反应分为5个步骤，总速率为3.267×106 m -1 s-1；第一步和第四步分别吸热 22.74 和 19.72 kJ/mol；第四步，在放热过程中，需要克服47.21 kJ/mol的Ea；反应机理涉及还原态的 Mn(II) 和氧化态的 Mn(III) 之间的相互转化以消耗过氧化氢。第二步伴随着137.23 kJ/mol的最大放热；活性中心的Cu2+通过消耗OO/H+被还原为Cu+，然后通过再次消耗OO将Cu+氧化为Cu2+。Mn过氧化氢酶与H2O2的歧化反应分为5个步骤，总速率为3.267×106 m -1 s-1；第一步和第四步分别吸热 22.74 和 19.72 kJ/mol；第四步，在放热过程中，需要克服47.21 kJ/mol的Ea；反应机理涉及还原态的 Mn(II) 和氧化态的 Mn(III) 之间的相互转化以消耗过氧化氢。第二步伴随着137.23 kJ/mol的最大放热；活性中心的Cu2+通过消耗OO/H+被还原为Cu+，然后通过再次消耗OO将Cu+氧化为Cu2+。Mn过氧化氢酶与H2O2的歧化反应分为5个步骤，总速率为3.267×106 m -1 s-1；第一步和第四步分别吸热 22.74 和 19.72 kJ/mol；第四步，在放热过程中，需要克服47.21 kJ/mol的Ea；反应机理涉及还原态的 Mn(II) 和氧化态的 Mn(III) 之间的相互转化以消耗过氧化氢。然后通过再次消耗 OO 将 Cu+ 氧化为 Cu2+ 。Mn过氧化氢酶与H2O2的歧化反应分为5个步骤，总速率为3.267×106 m -1 s-1；第一步和第四步分别吸热 22.74 和 19.72 kJ/mol；第四步，在放热过程中，需要克服47.21 kJ/mol的Ea；反应机理涉及还原态的 Mn(II) 和氧化态的 Mn(III) 之间的相互转化以消耗过氧化氢。然后通过再次消耗 OO 将 Cu+ 氧化为 Cu2+ 。Mn过氧化氢酶与H2O2的歧化反应分为5个步骤，总速率为3.267×106 m -1 s-1；第一步和第四步分别吸热 22.74 和 19.72 kJ/mol；第四步，在放热过程中，需要克服47.21 kJ/mol的Ea；反应机理涉及还原态的 Mn(II) 和氧化态的 Mn(III) 之间的相互转化以消耗过氧化氢。需要克服 21 kJ/mol；反应机理涉及还原态的 Mn(II) 和氧化态的 Mn(III) 之间的相互转化以消耗过氧化氢。需要克服 21 kJ/mol；反应机理涉及还原态的 Mn(II) 和氧化态的 Mn(III) 之间的相互转化以消耗过氧化氢。