【摘要】 氯过氧化物酶(CPO)是应用最广的一种过氧化物酶,能催化一系列底物的氧化。采用量子化学从头算方法在HF/6-31G(d)水平下计算了7种含S=P键的有机磷农药的多个量子化学参数,运用偏最小二乘法建立CPO对有机磷农药反应活性的定量结构-活性关系(QSAR)模型。结果表明,CPO对有机磷农药的反应活性与所考查的量子化学参数之间存在非线性关系。以对数关系建模得到了相关系数为0.910的模型,该模型具有较高的拟合精度和较强的预测能力。模型辅助分析表明,农药分子的S=P键中S原子电荷的大小对氧化活性的影响最大,P原子电荷大小的影响次之,分子偶极矩对氧化活性也有一定影响;农药分子中S原子带负电荷越多,P原子所带正电荷越多,分子极性越小,该农药就越容易被CPO催化氧化。最后运用所得模型预测了2种有机磷农药的CPO反应活性。更多还原

【Abstract】 Chloroperoxidase(CPO)is one of the most versatile peroxidases,which can catalyze the oxidation of a series of organic compounds.Quantitative structure-activity relationship(QSAR)modeling is a helpful approach used to correlate the activities of organic pollutants with their structure descriptors.Based on some quantum chemical descriptors computed at the HF/6-31G(d)level with the ab initio method of quantum chemistry,using partial least squares(PLS)method,QSAR models were obtained for the CPO reactivity of seven organophosphorus pesticides(OPPs)containing S=P bond.The results showed the relationships between the CPO reactivity of OPPs and the quantum chemical descriptors studied were nonlinear.The fitting results for the QSAR model,which correlated the CPO reactivity and the quantum chemical descriptors with logarithmic relationships and had a correlation coefficient of 0.910,showed that the model had a high fitting precision and a good predicting ability.PLS model assistant analysis showed that the sulfur atom charges in the S=P bond of the pesticide molecular had the greatest influence in governing the CPO reactivity,and the influence of phosphorus atom charges was secondary,while the molecular dipole moment also had some influence.It was found that OPPs with larger absolute values of atomic charges on the sulfur and phosphorus atoms tended to be metabolized faster,while OPPs with stronger polarity tended to be metabolized slower by CPO.The CPO reactivity of two OPPs without reported observed values were predicted.更多还原