Peptide-lipid interactions and mechanisms of antimicrobial peptides.

摘要: Hydrophobic matching, in which transmembrane proteins cause the surrounding lipid bilayer to adjust its hydrocarbon thickness match length of hydrophobic surface protein, is a commonly accepted idea. To test this idea, gramicidin was embedded dilauroyl phosphatidylcholine (DLPC) and dimyristoyl (DMPC) bilayers at molar ratio 1:10. The (PtP) measured by X-ray lamellar diffraction. In fluid phase near full hydration, PtP 30.8 A for pure DLPC, 32.1 DLPC/gramicidin mixture, 35.3 DMPC 32.7 DMPC/gramicidin mixture. Gramicidin apparently stretches DLPC thins toward common as expected matching. pair correlations were in-plane scattering. phase, gramicidin-gramicidin nearest-neighbour separation 26.8 but shortens 23.3 bilayers, thus confirming conjecture that when are membrane, matching creates strain field turn gives rise membrane-mediated attractive potential between proteins. These results analysed with an elasticity theory membrane deformation. same principle explains 'concentration-gating' mechanism pore formation antimicrobial peptides via membrane-thinning effect. Concentration-gated thinning alamethicin magainin have been observed.