INVESTIGATING BROMOFORM-MEMBRANE INTERACTIONS TO MITIGATE CLIMATE CHANGE USING ATOMISTIC SIMULATIONS

Abstract

Ruminant methane emission is one of the main factors contributing to global warming. To lower these emissions, one can use seaweed as a food additive, because seaweed is enriched in bromoform, an effective methanogenesis inhibitor. Ideally, bromoform amount in seaweed might be increased by engineering peroxisome organelles such that their storage capacity increases. For this, we must understand the fundamental interactions between bromoform and seaweed peroxisome membranes. To investigate these interactions, we generated new bromoform parameter and topology files in the CHARMM format and performed all-atom molecular dynamics simulations of water membrane solutions at varying bromoform concentrations. We used a pure phosphatidylcholine (POPC) bilayer since the peroxisome membrane composition is unknown. We validated the forcefield by contrasting our results with published experimental data and determined that bromoform aggregates at high concentrations due to its hydrophobic character. Moreover, bromoform penetrates the membrane in nanoseconds at low concentrations with a diffusion coefficient comparable to common small organic molecules (~10^-6 cm^2/s). In addition, bromoform determines an increase of the membrane thickness, which is positively correlated with the number of molecules penetrating the membrane. Our findings illustrate bromoform interactions with POPC membranes and represent proof of concept for further studies aiming at peroxisome engineering.