Peptides at lipid bilayers and at the air/water interface

Abstract

AbstractThere is a multitude of amphiphilic peptides which interact with lipid bilayers and biological membranes. From a physical chemical point of view a fundamental issue in this respect concerns the quantitative analysis of the involved partitioning equilibrium between a hydrophobic interface (lipid/water or air/water) in structural and thermodynamic terms. In the present article some relevant theoretical and experimental approaches are discussed and illustrated by means of special examples. Regarding lipid bilayers this comprises various problems of pertinent evaluation of measured data when an aqueous solution is titrated with lipid vesicles. On the other hand, a novel method is presented that makes it possible to derive and interpret true surface concentrations at an air/water interface of a Langmuir trough with peptide or other surfactant material if only a comparably small part of the substance seeps away from the monolayer into the subphase.