Molecular dynamics studies of interactions between Arg9(nona-arginine) and a DOPC/DOPG(4:1) membrane

TL;DR

This study uses molecular dynamics simulations to explore how temperature affects Arg9 peptide penetration into a specific lipid membrane, revealing key factors like water coordination and electrostatic interactions that influence membrane penetration.

Contribution

It provides new insights into the temperature-dependent mechanisms of Arg9 peptide interaction with lipid membranes through detailed MD simulations.

Findings

Water molecules coordinated with Arg9s influence penetration

Electrostatic energy correlates with peptide-membrane interaction

Membrane bending is affected by Arg9s and their collective behavior

Abstract

It has been known that the uptake mechanisms of cell-penetrating peptides(CPPs) depend on the experimental conditions such as concentration of peptides, lipid composition, temperature, etc. In this study we investigate the temperature dependence of the penetration of Arg9s into a DOPC/DOPG(4:1) membrane using molecular dynamics(MD) simulations at two different temperatures, T = 310 K and T = 288 K. Although it is difficult to identify the temperature dependence because of having only one single simulation at each temperature and no evidence of translocation of Arg9s across the membrane at both temperatures, our simulations suggest that followings are strongly correlated with the penetration of Arg9s: a number of water molecules coordinated by Arg9s, electrostatic energy between Arg9s and the lipids molecules. We also present how Arg9s change a bending rigidity of the membrane and how a collective behavior between Arg9s enhances the penetration and the membrane bending. Our analyses can be applicable to any cell-penetrating peptides(CPPs) to investigate their interactions with various membranes using MD simulations.