Issue 49, 2017

Molecular-level insight into the binding of arginine to a zwitterionic Langmuir monolayer

Abstract

Solutions of the cationic amino-acid arginine (Arg+) in contact with a phospholipid monolayer are investigated by molecular dynamics simulations. The results show that Arg+ binds strongly to the lipid/water interface, with adsorption free-energies ranging from −43.8 to −22.2 kJ mol−1, depending on the amino-acids concentration. The large binding energies are attributed to hydrogen bonding between the charged moieties Arg+ and the phosphate and carbonyl groups of the phospholipids, that compensate for changes in the levels of hydration upon adsorption. We show that a concentrated layer of Arg+, tightly bound to the interface, has little effect on the compression isotherm and the lateral mechanical properties of the monolayer, while having a substantial impact on the interfacial electrostatic potential and the lateral mobility of the lipids. These effects are readily explained in terms of the arrangement that the amino-acids adopt when bound to the monolayer.

Graphical abstract: Molecular-level insight into the binding of arginine to a zwitterionic Langmuir monolayer

Supplementary files

Article information

Article type
Paper
Submitted
12 May 2017
Accepted
08 Jun 2017
First published
14 Jun 2017
This article is Open Access
Creative Commons BY license

RSC Adv., 2017,7, 30862-30869

Molecular-level insight into the binding of arginine to a zwitterionic Langmuir monolayer

J. Klug, D. Masone and M. G. Del Pópolo, RSC Adv., 2017, 7, 30862 DOI: 10.1039/C7RA05359B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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