Eur. Phys. J. E (2018) 41: 44
https://doi.org/10.1140/epje/i2018-11644-5

Regular Article

The effect of gramicidin inclusions on the local order of membrane components

¹ Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405, Orsay Cedex, France
² UMR 7099, CNRS-Université Paris Diderot, Institut de Biologie Physico-Chimique, Paris, France
³ Département de Chimie, Université du Québec à Montréal, Downtown Station, P.O. Box 8888, H3C 3P8, Montreal, Canada

^* e-mail: doru.constantin@u-psud.fr

Received: 17 July 2017
Accepted: 7 March 2018
Published online: 28 March 2018

Abstract

We study the local effect of the antimicrobial peptide Gramicidin A on bilayers composed of lipids or surfactants using nuclear magnetic resonance spectroscopy and wide-angle X-ray scattering, techniques that probe the orientational and positional order of the alkyl chains, respectively. The two types of order vary with temperature and peptide concentration in complex ways which depend on the membrane composition, highlighting the subtlety of the interaction between inclusions and the host bilayer. The amplitude of the variation is relatively low, indicating that the macroscopic constants used to describe the elasticity of the bilayer are unlikely to change with the addition of peptide.