Abstract

F. Mollaamin*, K. Shahani poor, T. Nejadsattari and M. Monajjemi

A cluster model for active site of oxidized azurin was presented and investigated the geometric structure and thermochemical parameters. Quantum-mechanical calculations were performed at the HF and B3lYP/6-31G levels of theory in the gas phase and eight solvents at four temperatures. Also, nuclear shielding parameters of the active site of oxidized azurin have been taken into account using GIAO and CSGT methods at the HF and B3LYP/6-31G levels of theory in the gas phase and in different solvents such as water, DMSO, nitromethane, methanol, ethanol, acetone, dichloroethane and dichloromethane. The results were revealed that the NMR chemical shielding parameters are strongly affected by inducing different solvent media. According to these theoretical results of energy values, some important relationships have been found between the dielectric constant and structural stability of active site of oxidized azurin. Thus, it can be drastically concluded that the dielectric permittivity of the solvent is a key factor that determines the chemical behavior of active site azurin in solution.