The Possibility of Pore Formation in Lipid Membranes by Several Molecules of Amphipathic Peptides

Abstract

Antimicrobial activity of some amphipathic peptides is associated with the formation of through pores in bacterial membranes. Antimicrobial peptides (AMPs) specifically bind to the plasma membrane by incorporating their hydrophobic regions into the outer lipid monolayer. The membrane is inevitably deformed. Many AMPs form so-called toroidal pores, the edge of which is partially lined with peptide molecules. The edge of the pore is characterized by significant deformations. In this work, we calculated the energy of the pore edge, with amphipathic peptides located on the pore equator, as well as the energy of deformations induced by AMP in a planar lipid bilayer. It was shown that for certain physicochemical and geometric characteristics of the AMP molecule the energy of the pore, on the equator of which two or more peptide molecules are located, can be lower than the energy of deformations induced in the planar bilayer by the same number of peptide molecules. Thus, two AMP molecules can, in principle, form a through pore in the membrane, although this is possible only in a fairly narrow range of physicochemical and geometric characteristics of the peptides.