Investigation of electrostatic force and dipole moment effects on movement and dancing of Chains in DPPC and DMPC

Abstract

An understanding of static properties of membrane is an essential prelude to the study of movement of molecules within the membrane. In this investigation any molecule has been theoretically investigated through the quantum mechanical calculations.According to the results obtained, the structural optimization of the isolated Dipalmitoylphosphatidylcholine (DPPC ) and  Dimyristoylphosphatidylcholine (DMPC) in the gas phase, at the Hartree-Fock level of theory, apply to STO-3G,3-21G, 6-31G and 6-31G* basis sets. The most important dihedral angle of these molecules was chosen and the energy, dipole moment, and atomic charges of 14 important atoms were scanned within 180 degrees rotation and sites that have most changes were determined and any rotated molecule was separately placed in 19 solvents (The method is HF/6-31G* model) and the dielectric effect of the surrounding was analyzed. Quantum chemical solvent effect theories describe the electronic structure of a molecular subsystem embedded in a solvent or other molecular environment.The solvent effect on the stability of DPPC & DMPC molecules, dipole moment, and the charge on some atoms of those molecules are discussed using Onsager model.