Quantum-chemical and empirical calculations on phospholipids. VI: The stereospecific interaction of Na+ with phosphatidylethanolamine and with phosphatidylcholine layer systems

✍ Scribed by H. Frischleder; G. Peineil

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 468 KB
• Volume: 27
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(80)90049-3

✦ Synopsis

Using 1-6-12 atom-atom potential functions with a solvent-averaged electrostatic potential U = qlqi/(~D(r)rli) between the charges ql and qj the stereospecific interaction of Na* with clusters of L-glycero-phosphorylethanolamine (GPE) and -choline (GPC) in a two-dimensional planar lattice was calculated. With neutral PE headgroups 0nly a weak attractive interaction of -140kJ/mol was found. This should be compensated in PE/water systems by reorientational processes within the Na ÷ hydration shell to get an optimum binding of Na ÷ with the PE headgroup. With a phosphorylethanolamine anion within a neutral PE headgroup environment a stereospecific binding energy of -500 kJ/mol was calculated. The interaction of Na + or Ca 2+ with clusters of phosphatidylcholine is always repulsive. These results are in a very good agreement with experimental ones where a binding of Na ÷ with PE bilayers at pH > 7.5, but not with PC bilayers was detected.