Impact of Lipid Structural Variations on Bilayer Properties: A Coarse-Grained Molecular Dynamics Study

TL;DR

This study uses coarse-grained molecular dynamics simulations to analyze how lipid structural variations affect bilayer properties, revealing key relationships between lipid composition and membrane biophysical characteristics.

Contribution

It provides new insights into how acyl chain length, unsaturation, and headgroup type influence bilayer structure and dynamics using the Martini force field.

Findings

Longer acyl chains increase bilayer thickness

Unsaturation reduces bilayer thickness and increases area per lipid

Unsaturated lipids have higher lateral diffusion coefficients

Abstract

The supramolecular assembly of lipids into bilayer membranes is essential for cellular structure and function. However, the impact of lipid structural variations such as acyl chain length, degree of unsaturation, and headgroup type on bilayer properties remains incompletely understood. This study employs coarse-grained molecular dynamics simulations using the Martini force field to investigate seven distinct lipid species, aiming to compute critical bilayer parameters including area per lipid, bilayer thickness, and lateral diffusion coefficients. Our simulations reveal that lipids with longer acyl chains exhibit increased bilayer thickness, while unsaturation introduces kinks in the acyl chains, generally reducing bilayer thickness and increasing the area per lipid. Lipids with unsaturated chains demonstrate higher lateral diffusion coefficients, enhancing membrane fluidity. Variations in headgroup chemistry significantly influence lipid packing and membrane dynamics. This investigation advances our understanding of membrane biophysics and has significant implications for the design of lipid-based systems in biomedical applications.