Extreme pH-induced lateral reorganization of supported lipid bilayer by fluorescence microscope

Abstract

The extreme pH-induced lateral reorganization of supported lipid bilayer membranes are studied by fluorescence microscopy. The results show that the fluid dioleoyl-phosphatidylcholine bilayers in extreme acidic or basic solution presents a similar phenomenon to endocytosis and exocytosis, such as rupture, detachment, budding, formation of microtubules etc. In the view of the interaction of polar molecules with H+/H3O+ or OH ions, we conclude that the zwitterionic phospholipid headgroup as core adsorbs the H+/H3O+ or OH ions in electrolyte solution. The asymmetric charge adsorption quantity of the lipid headgroups leads to the effective area discrepancy between the outer and inner leaflets of lipid bilayers. The asymmetric membrane curvatures induce a variety of structures and dynamic responses. The present study helps explain lipid membranes reorganization under extreme pH conditions and provides some guidelines for deformation process of lipid membranes.