用氧化水观点解释酶促过氧化氢歧化分解的反应机理

A New Mechanism of Disproportionation Decomposition of H 2O 2 by Catalase Catalysis

认为过氧化氢酶（ＥＣ１．１１．１．６）催化过氧化氢歧化分解反应的机理是：过氧化氢酶结合一分子Ｈ２Ｏ２形成化合物Ⅰ后，催化该Ｈ２Ｏ２异构化为一种氧化性能很强的Ｈ２Ｏ－Ｏ，然后，放出活性氧原子去氧化另一个Ｈ２Ｏ２分子产生２Ｈ２Ｏ和Ｏ２；并认为Ｈ２Ｏ２异构化为Ｈ２Ｏ－Ｏ是该总反应的控制环节。据此观点，进行了单分子反应理论ＲＲＫＭ计算，其结果和实验基本一致。

A new mechanism of disproportionation reaction for catalase catalytic decomposition of hydrogen peroxide is discussed,namely,isomerization of HOOH-H 2OO is accelerated by catalase catalysis and oxywater,H 2O-O,is produced,it is following step that another H 2O 2 is oxidized by the H 2O-O producing 2H 2O molecules,but O 2 molecule come of the H 2O 2.On the basis of the mechanism,the rate coefficients of H 2O 2 decomposition obtained by RRKM calculation are basically compatible with experimental values.