Monovalent cations differentially affect membrane surface properties and membrane curvature, as revealed by fluorescent probes and dynamic light scattering.

摘要: The effects of monovalent cations on the interfacial electrostatic potential (ψd), hydrodynamic shear boundary distance (ds), and membrane curvature were studied in large unilamellar phospholipid galacto/sulfolipid liposomes containing different fractions negatively charged lipids. differential alkali metal ions ψd could be accurately determined at physiological surface charge densities with a surface-anchored fluorescent probe. Li+ Na+ more effectively decrease exhibit higher association constants (Kas) than K+ Cs+. These two groups display qualitatively perturbations structure. Combining Kas values electrokinetic (ζ) potentials yielded respective ds values. At low ionic strength substantially increases or Increasing density causes increased presence Cs+, but this is largely prevented by Na+. Membrane binding amphiphilic cation acridine orange decreases extensively H3O+, Li+, interface-perturbing behavior discussed regard to their hydration tendencies that will modulate extent stability hydrogen-bond network along surface.