Conformation of ultra-long-chain fatty acid in lipid bilayer: Molecular dynamics study

TL;DR

This study uses molecular dynamics simulations to explore how ultra-long-chain fatty acids behave within lipid bilayers, revealing their ability to flip and sense leaflet density differences, which impacts membrane properties.

Contribution

It provides novel insights into the dynamic behavior and sensing mechanism of ULCFAs in lipid bilayers through detailed molecular dynamics analysis.

Findings

ULCFAs flip between leaflets and fluctuate among different conformations.

The elongated shape ratio decreases linearly with increased opposite leaflet lipids.

ULCFAs can sense and respond to density differences between membrane leaflets.

Abstract

Ultra-long-chain fatty acids (ULCFAs) are biosynthesized in the restricted tissues such as retina, testis, and skin. The conformation of a single ULCFA, in which the sn-1 unsaturated chain has 32 carbons, in three types of tensionless phospholipid bilayers is studied by molecular dynamics simulations. It is found that the ultra-long tail of the ULCFA flips between two leaflets and fluctuates among an elongation into the opposite leaflet, lying between two leaflets, and turning back. As the number ratio of lipids in the opposite leaflet increases, the ratio of the elongated shape linearly decreases in all three cases. Thus, ULCFAs can sense the density differences between the two leaflets and respond to these changes.