铁卟啉与O2、N2、NO结合后的金属自旋状态分析

摘要

To investigate the binding modes between iron porphyrins and the three kinds of gas molecules, O2 , NO and N2 in the hemoglobin, analyze the influence on the binding modes by three spin states ( low, medium, high spin states ) of the three gas molecules. Using semi-empirical quantum chemistry calculation software MOPAC 2012, parameters were tuned and the binding free energy was calculated. When the iron porphyrin was combined with O2 , the binding energy was lowest in the high spin state, which was -96. 19 kJ/mol;combined with N2 ,the binding energy was -48. 87 kJ/mol in the low spin state;combined with the NO, the binding energy was -85. 60 kJ/mol in the low spin state.%通过半经验量子化学计算软件 MOPAC2012 研究血红蛋白中铁卟啉与3种气体分子O2、NO和N2 在低、中、高3种自旋状态下的结合作用,计算体系中的基本机构参数和总能量变化,分析自旋状态在血红蛋白中结合气体分子的作用. 铁卟啉结合O2 分子时,在高自旋状态时结合能最低,为-96. 19 kJ/mol;结合N2 分子时,在低自旋状态时结合能最低,为-48. 87 kJ/mol;结合NO分子时,在低自旋状态时结合能最低,为-85. 60 kJ/mol.