Investigating the Bromoform Membrane Interactions Using Atomistic Simulations and Machine Learning: Implications for...

Area of Science:

• Biophysics
• Environmental Science
• Biochemistry

Background:

• Livestock methane emissions contribute to global warming.
• Seaweeds, as a feed additive, show potential for mitigating these emissions due to bromoform, a methanogenesis inhibitor.
• Understanding bromoform's behavior within cellular environments is key to its application.

Purpose of the Study:

• To provide an atomistic description of bromoform dynamics, diffusion, and aggregation near lipid membranes.
• To investigate bromoform-lipid bilayer interactions at various concentrations.
• To elucidate bromoform's localization and transport within a membrane-like environment.

Main Methods:

• All-atom molecular dynamics simulations.
• Customized CHARMM-formatted bromoform force field.
• Analysis of membrane properties (thickness, lipid tail order, curvature).
• General local-atomic descriptors and unsupervised machine learning for structural analysis.

Main Results:

• Bromoform penetrates lipid membranes.
• At high concentrations, bromoform forms aggregates outside the membrane, influencing membrane curvature but not thickness or lipid order.
• Bromoform localizes in the hydrophobic core and exhibits slowest diffusion along the membrane normal.
• Local structures of bromoform in liquid and aggregated forms are similar.

Conclusions:

• Bromoform's interaction with lipid membranes is concentration-dependent.
• Bromoform aggregation outside the membrane suggests a mechanism for its biological activity.
• This atomistic insight is foundational for developing seaweed-based methane emission reduction strategies.