The DFT-DVM theoretical study of the differences of quadrupole splitting and the iron electronic structure for the rough heme models for alpha- and beta-subunits in deoxyhemoglobin and for deoxymyoglobin

Abstract

Quantum chemical calculations of the iron electron structure and (57)Fe quadrupole splitting were made by density functional theory and X alpha discrete variation method for the rough heme models for alpha- and beta-subunits in deoxyhemoglobin and for deoxymyoglobin accounting stereochemical differences of the active sites in native proteins. The calculations revealed differences of quadrupole splitting temperature dependences for three models indicating sensitivity of quadrupole splitting and Fe(II) electronic structure to small variations of iron stereochemistry.