[Intensification of the ionophoric effect of polymyxin M by free fatty acids. Dependence of the length of the fatty acid chain].

Mechanisms of potentiation of ionophoric effect of polymyxin M by free fatty acids was studied using measurement of electrical properties of bilayer lipid membranes. Among used unsaturated fatty acids the palmitic acid appeared to be the most effective. The obtained dependence of ionophoric effect of membrane antibiotic on the chain length of the fatty acid may be explained by the existence of the complex of special size appropriate to the membrane thickness. We suppose that free fatty acid and polymyxin M form the ion-conducting structure in lipid bilayer.