Abstract:

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.

Key words: atombond electronegativity equalization method, hemerythrin, charge distribution, Fukui function, carrying oxygen functions