蚯蚓血红蛋白载氧功能的Fukui函数

采用原子 键电负性均衡方法, 计算蚯蚓血红蛋白活性中心原子的电荷分布及Fukui函数. 在脱氧蚯蚓血红蛋白活性中心的两个铁离子中, 即将结
合氧分子的铁离子Fukui函数最大, 表明该铁离子具有很高的活性, 易与氧结合. 在氧合蚯蚓血红蛋白中, 结合氧分子后的铁离子Fukui函数小于结合氧分子中质子化的氧原子Fukui函数, 同时该质子化的氧原子具有最大的Fukui函数, 表明氧合蚯蚓血红蛋白的活性中心由铁离子转移到质子化的氧原子. 应用该方法计算了脱氧蚯蚓血红蛋白活性中心与抑制剂中叠氮、 氯等配体结合的Fukui函数. 计算结果表明, 活性中心铁离子的Fukui函数分别小于与其配位的氮和氯原子的Fukui函数, 从而验证了蚯蚓血红蛋白的载氧功能被抑制或减弱.

Fukui Function for Performance of Hemerythrin Carrying

The charge distribution and Fukui function of the atoms of the active central site of the hemerythrin were calculated in terms of the atom-bond electronegativity equalization method(ABEEM).In the two iron atoms of deoxyhemerythrin,Fukui function of one iron atom which is about to bind O2 is the biggest.This shows that the iron atom in deoxyhemerythrin has a high activity,that is,it easily carrys O2.Fukui function of the iron atom binding O2 is smaller than that of the protonated oxygen atom in O2.This also shows that hemerythrin can release O2.When the deoxyhemerythrin binds the potassium cyanide and sodium azide inhibitions,the Fukui functions of the two iron atoms are smaller than those of the Cl and N coordinated atoms.The function of deoxyhemerythrin carrying O2 is weakened or inhibited,which is in agreement with the experiment.