Quasi-Elastic and Electrophoretic Light Scattering Studies of the Reorganization of Dioleoylphosphatidylcholine Vesicle Membranes by Poly(2-Ethylacrylic Acid).

摘要

Quasi-elastic light scattering (QELS) and electrophoretic light scattering (ELS) measurements have been used to investigate the pH-dependent structural reorganization of phospholipid vesicles suspended in aqueous solutions of poly(2-ethylacrylic acid) (PEAA). The average radius of dioleoylphosphatidylcholine (DOPC) vesicles suspended in aqueous PEAA was reduced within 1 h from approximately 600 to 60 nm upon acidification. Size distribution analysis revealed narrow single peaks far from the pH at which the reorganization occurs but bimodal distributions in the transition region. Surfactant bilayers have been a subject of intense scientific interest for the last 2 decades, since Bangham's illustration of the analogy between such 'liposomal' structures and the complex plasma membranes of cells. An essential and intriguing characteristic of the natural membranes is their capacity to respond to signals of various kinds; membrane signaling plays a critical role in intercellular communication, in the binding and processing of ligands and receptors, in energy transduction, and in many other vital cellular processes. (jes)