Quantum chemical studies of redox-active enzymes.
Quantum chemical studies of redox-active enzymes.
复制标题
氧化还原活性酶的量子化学研究。
作者：
P. Siegbahn
在金属酶机理的研究中，杂化密度泛函方法B3 LYP已被广泛应用。目前的知识，这种方法对过渡金属络合物的准确性进行了描述。与从头算方法如CASPT 2和CCSD（T）相比，B3 LYP通常表现得相当好。然而，有一个例外，这是在血蓝蛋白，儿茶酚氧化酶和酪氨酸酶等酶中发现的铜二聚体类型。在CASPT 2和B3 LYP之间以及B3 LYP和模型配合物的实验之间已经发现了很大的偏差。这一情况得到了认真调查。通过与实验的比较，还分析了B3 LYP对酶中O2活化的准确性。对于O-O键断裂的势垒，B3 LYP表现得相当令人满意，而对于O2与金属的结合，与实验相比存在偏差。这是否是由于B3 LYP方法或所使用的化学模型的问题得到解决。
In applications on mechanisms for metalloenzymes, the hybrid density functional method B3LYP has been used in most cases. The present knowledge about the accuracy of this method on transition metal complexes is described. In comparison to ab initio methods like CASPT2 and CCSD(T), B3LYP has generally been shown to perform quite well. However, there is one exception and this is for the type of copper dimer which is found in enzymes like hemocyanin, catechol oxidase and tyrosinase. Large deviations have been found between CASPT2 and B3LYP and also between B3LYP and experiments on model complexes. This situation is carefully investigated. The accuracy of B3LYP for the activation of O2 in enzymes is also analyzed by comparisons to experiments. For the barrier of O-O bond cleavage B3LYP appears to behave quite satisfactorily, while for the binding of O2 to the metal there are deviations compared to experiment. The question whether this is due to the B3LYP method or to the chemical models used is addressed.