Single Giant Unilamellar Vesicle Method Reveals Effect of Antimicrobial Peptide, Magainin 2, and Antibacterial Substance, Tea Catechin, on Membrane Permeability and Membrane Structure

Abstract

Almost all studies of biomembrane function have previously been carried out on suspensions of many small-size vesicles such as large unilamellar vesicles (LUVs). In these studies, the average values of the physical parameters of vesicles have been obtained from large numbers of vesicles, and thereby a lot of information has been lost. Recently we have proposed a novel method, the single GUV method. In this method we observe and measure physical properties of single giant unilamellar vesicles (GUVs) with diameters ? 10 ?m, and analyze these results over many GUVs statistically, which will provide a lot of novel information that cannot be obtained by the studies of suspensions of small-size vesicles. In this report, we investigated effect of antimicrobial peptide, magainin 2, and antibacterial substance, tea catechin, on structure and physical property of lipid membranes using the single GUV method, and succeeded in obtaining detailed information of their effects on lipid membranes.