Quantum-chemical and empirical calculations on Phospholipids VIII. The electrostatic potential from isolated molecules up to layer systems

✍ Scribed by G. Peinel; H. Frischleder; H. Binder

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 496 KB
• Volume: 33
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(83)90021-x

✦ Synopsis

Using 1-6-12 empirical functions with a solvent-averaged electrostatic contribution qrqj/e (rlj)× rtj and electrostatic potentials from CNDO-type wavefunctions, the development of specific interactions of ions visualized by the molecular electrostatic potential of PO4-group containing molecules was studied. Going from single molecules to monolayers made up of 37 head groups of phosphatidylcholine (PC) o r phosphatidylethanolamine (PE) for quantum-chemical calculations, or of 23 head groups for empirical calculations we found decreasing potential minima. Only the inclusion of the screening effect of water, simulated by a distance dependent dielectric constant, e (r), gives an explanation of stereospecific interactions of model membranes with ions. This finding can be compared with results of simulation calculations on water structure above a PE head group layer.