Identifying the Pathways to Permeation through OccD1 in the Outer Membranes of P. Aeruginosa

Simulating Gram-Negative Bacterial Outer Membrane: A Coarse Grain Model

“…Integral components of the bacterial outer membrane are the β-barrel OMPs, also called porins, which provide nonspecific channels for translocation of small hydrophilic molecules (less than 0.6 kDa) across the membrane. − Although the translocation through the porins is passive, the channels can be charge and size selective based on the charge distribution in the lumen of the β-barrel scaffold. For example, Pseudomonas aeruginosa has outer membrane carboxylate channels (Occ) that are substrate-specific and are considered to be responsible for the uptake of a majority of small molecules, including antibiotics . There are reports where porins have been purified, reconstituted, and even engineered to analyze their selectivity and voltage gating to determine the mechanism of antibiotic translocation through the channels. , …”

“…For example, Pseudomonas aeruginosa has outer membrane carboxylate channels (Occ) that are substrate-specific and are considered to be responsible for the uptake of a majority of small molecules, including antibiotics. 32 There are reports where porins have been purified, reconstituted, and even engineered to analyze their selectivity and voltage gating to determine the mechanism of antibiotic translocation through the channels. 33,34 Numerous experimental techniques such as neutron diffraction, 35 small-angle scattering, 36 Fourier transform infrared spectroscopy, 37,38 differential scanning calorimetry, 38 smallangle X-ray diffraction, 36,39 nuclear magnetic resonance (NMR), 40 and transmission electron spectroscopy 41 have been employed to investigate bacterial membranes, but detailed characterization of the outer membrane is often difficult due to the chemical heterogeneity in the membrane composition and polymorphism of the LPS macromolecule.…”