Peptide-Lipid Interactions of the Stress-Response Peptide TisB That Induces Bacterial Persistence

摘要: The bacterial stress-response peptide TisB in Escherichia coli has been suggested to dissipate the transmembrane potential, such that depletion of ATP levels induces formation dormant persister cells which can eventually form biofilms. We studied structure and membrane interactions find out whether it forms pores or other proton-selective channels. Circular dichroism revealed an amphiphilic α-helical when reconstituted lipid vesicles, oriented circular showed helix assumes a alignment. addition dye-loaded vesicles caused leakage only at very high concentration, notably with Hill coefficient 2, suggests dimers must be involved. Coarse-grained molecular dynamics simulations binding monomeric is rapid spontaneous, insertion energetically feasible. When oligomers are assembled as pores, these channels collapse during simulations, but found stable. Given pattern charges on helix, we postulate antiparallel could via ladder salt bridges. This electrostatic charge-zipper enable protons pass along wire trapped water molecules across hydrophobic membrane.