Effects of lipid composition on membrane permeation

Area of Science:

• Biophysics
• Computational Chemistry
• Pharmacology

Background:

• Biological membranes are crucial for cell function and are composed of lamellar and nonlamellar lipids.
• Nonlamellar lipids influence membrane properties like stress and elasticity, potentially affecting biological processes such as permeation.
• Understanding lipid composition effects on membrane permeation is vital for drug development.

Purpose of the Study:

• To investigate the impact of nonlamellar lipids on the permeation of small molecules and drugs across lipid bilayers.
• To determine how lipid composition affects membrane properties relevant to passive permeation.
• To advance the development of accurate in silico permeability assays for rational drug design.

Main Methods:

• Atomistic molecular dynamics simulations were employed to model membrane permeation.
• Transfer free energy profiles, diffusion profiles, and permeation coefficients were calculated.
• Thirteen small molecules and drugs were simulated across purely lamellar and mixed lamellar/nonlamellar lipid bilayers.

Main Results:

• The presence of nonlamellar lipids significantly altered permeation characteristics compared to purely lamellar membranes.
• Nonlamellar lipids reduced permeation for smaller molecules (molecular weight < 100).
• Conversely, nonlamellar lipids facilitated permeation for larger molecules (molecular weight > 100).

Conclusions:

• Nonlamellar lipids play a differential role in membrane permeation based on molecular size.
• These findings contribute to more realistic in silico models for predicting drug permeability.
• The study has significant implications for rational drug design and the development of predictive computational assays.