Why Can Hydrogen Sulfide Permeate Cell Membranes?

摘要

The high membrane permeability of H_2S was studied using polarizable molecular dynamics simulations of a DPPC lipid bilayer. The solubility-diffusion model predicts permeability coefficients of H_2S and H_2O that are in good agreement with experiment. The computed diffusion coefficient profile shows H_2S to diffuse at a lower rate than H_2O, but the barrier for H_2S permeation on the Gibbs energy profile is negligible. The hydrophobicity of H_2S allows it to partition into the paraffinic interior of the membrane readily.