Molecular Mechanics Calculations on a New Model Compound Cu(II)-Zn(H)-Superoxide Dismutase

The X-ray structure of a new model compound of Cu(II)-Zn(II)-super- oxide dismutase, [N,N-butylenebis(2-acetylpyridineiminato)]copper(II) perchlorate was subjected to molecular mechanics calculations in order to reproduce the shape of the copper(II) coordination polyhedron. Altogether, six force fields were used; three of them yielded good agreement between theory and experiment, the rest gave structures highly distorted from planarity. The results suggest inadequacy of some molecular mechanics models for the simulation of highly distorted structures