Microelectrophoretic investigation of the interactions between liposomal membranes formed from a phosphatidylcholine-phosphatidylglycerol mixture and monovalent ions

Abstract

Abstract. In this paper, we characterized the interactions between two-component liposomal membranes and monovalent electrolyte ions. Liposomes were formed from neutral (phosphatidylcholine) and anionic (phosphatidylglycerol) lipids mixed in various ratios. Microelectrophoresis was used to determine the dependence of the membrane surface charge density on the pH of the electrolyte solution. Changes in the membrane electric charge caused by the adsorption of Na + , Cl − , H + , and OH − ions were observed, and the equilibria among these ions and the phosphatidylcholine-phosphatidylglycerol membrane surface were quantified. We proposed a mathematical model for characterizing these equilibria. Using this model, together with experimental data of the membrane surface charge density, we determined association constants characterizing the equilibria. Knowledge of these parameters was necessary to calculate the theoretical curves of the model. We validated the model by curve-fitting the experimental data points to simulated data generated by the model.

Adsorption of Monovalent Ions to Phosphatidylcholine-Cardiolipin Membranes

“…This work continues the systematic study of the electrical properties of model membranes undertaken by Figaszewski and co-workers (12)(13)(14)(15), examining the effect of monovalent ion adsorption on the electric charge of phosphatidylcholine-cardiolipin liposomal membranes. The effect of lipid composition on membrane surface charge was also analyzed.…”

Association of alkali metal cations with phosphatidylcholine liposomal membrane surface

“…The present work continues the research of Figaszewski and coworkers on the adsorption of monovalent ions in aqueous solutions of alkali metal chlorides on liposomal membranes (Dobrzyńska et al 2007 ; Kotyńska et al 2008 ; Kotynska and Figaszewski 2014 , 2015 ). PC was chosen for this study because it is the most widespread and dominant of the membrane phospholipids, and it is well understood and described in detail by biomembrane researchers.…”

Electrophoretic Light Scattering and Electrochemical Impedance Spectroscopy Studies of Lipid Bilayers Modified by Cinnamic Acid and Its Hydroxyl Derivatives

“…Therefore, this paper is focused on the effect of cinnamic acid and its derivatives on the resistance, capacitance, and the surface charge density of model membranes (spherical lipid bilayers and liposomes). We previously described changes in the electrical parameters caused by e.g., membrane compositions in lipid-lipid [34], lipid-sterol [35], lipid-fatty acid [36], or lipid-carotenoid membranes [37]. The investigations reported in this paper are a continuation of the studies on the interaction of model membranes of increasing complexity with naturally occurring phenolic compounds.…”