Phospholipid Saturation Modulates Cholesterol Partitioning and Heat Transport in Lipid Bilayers under Thermal...

Area of Science:

• Membrane biophysics
• Computational biophysics
• Lipid bilayer dynamics

Background:

• Lipid asymmetry is crucial for membrane function.
• Thermal gradients exist in biological systems and are relevant to therapies.
• Understanding membrane behavior under nonequilibrium conditions is important.

Purpose of the Study:

• Investigate cholesterol partitioning in lipid bilayers under thermal gradients.
• Examine the influence of lipid saturation and cholesterol content.
• Determine how these factors affect mass and thermal transport.

Main Methods:

• Nonequilibrium molecular dynamics simulations.
• Coarse-grained MARTINI 3 force field.
• Simulations of lipid bilayers with varying lipid saturation and cholesterol content.

Main Results:

• Cholesterol exhibits thermophobic behavior, accumulating in colder regions.
• Thermophobicity is more pronounced in saturated lipid bilayers and at low cholesterol concentrations.
• Bilayer thermal conductivity decreases with increasing cholesterol content.
• Saturated phospholipid bilayers show higher thermal conductance than unsaturated ones.

Conclusions:

• Lipid composition and cholesterol content significantly modulate mass and thermal transport in lipid membranes.
• Cholesterol's thermophobic behavior is a key factor in membrane response to thermal stress.
• Findings are relevant to understanding membrane function under physiological and therapeutic thermal conditions.