Charge density distribution and electrostatic moments of N-(4-chloro-3-trifluromethyl-phenyl)-2-ethoxy-benzamide molecule at the active site of p300 enzyme: A quantum chemical and theoretical charge density study

摘要

A Charge density analysis of CTB molecule in gas phase (Form I) and the same present at the active site (Form II) of p300 enzyme were performed for the wave functions obtained from the Density functional method (B3LYP) with the basis set 6-311G**. This study has been carried out to understand the nature of conformational modification, charge redistribution and the change of electrostatic moments of the CTB molecule when present at the active site of p300. The difference of charge density distribution between both forms of CTB molecule explicitly indicates the effect of intermolecular interaction on CTB molecule in the active site. The dipole moment of CTB in the gas phase (9.6 D) has been significantly decreased (4.27 D) when it present at the active site of p300; this large variation is attributed to the charge redistribution in CTB, due to the intermolecular interaction between the CTB and the receptor p300 molecule. The electrostatic potential maps differentiate the difference of electrostatic potential between the two forms. A large electronegative region is found at the vicinity of oxygen and fluorine atoms.