ANALYSIS OF THE EFFECT OF MONO-VALENT AND DI-VALENT CATIONS ON THE FORCES BETWEEN CHARGED LIPID-MEMBRANES WITH SPECIAL REFERENCE TO THE GRANA THYLAKOIDS OF CHLOROPLASTS

A numerical technique is applied to the investigation of salt effects on the electrostatic repulsion between lipid membranes with chargeable anionic groups. It is found that when such groups dissociate easily, the effects of mono- and divalent cations are antagonistic under low salt conditions. However, when the surface anionic groups have pK values closer to the bulk pH value, the effects are much more subtle. The results of the analysis are applied to explain experimental observations on chloroplast grana thylakoid membranes, but they may find more general use. © 1979.