title: Binding of pediocin PA-1 with anionic lipid induces model membrane destabilization.
abstract: To obtain molecular insights into the action mode of antimicrobial activity of pediocin PA-1, the interactions between this bacteriocin and dimyristoylphosphatidylcholine (DMPC) or dimyristoylphosphatidylglycerol (DMPG) model membranes have been investigated in D(2)O at pD 6 by Fourier transform infrared spectroscopy. The interactions were monitored with respect to alteration of the secondary structure of pediocin, as registered by the amide I' band, and phospholipid conformation, as revealed by the methylene nu(s)(CH(2)) and carbonyl nu(C;O) stretching vibrations. The results show that no interaction between pediocin and DMPC occurs. By contrast, pediocin undergoes a structural reorganization in the presence of DMPG. Upon heating, pediocin self-aggregates, which is not observed for this pD in aqueous solution. The gel-to-crystalline phase transition of DMPG shifts to higher temperatures with a concomitant dehydration of the interfacial region. Our results indicate that pediocin is an extrinsic peptide and that its action mechanism may lie in a destabilization of the cell membrane.
authors: Centre de recherche en Sciences et Technologie du Lait (STELA), and Institut sur les nutraceutiques et aliments fonctionnels (INAF), Département des sciences des aliments et de nutrition, Université Laval, Pavillon Paul-Comtois, Sainte-Foy, Québec, Canada.
authors: Hélène
authors: H
authors: Gaussier
authors: Thierry
authors: T
authors: Lefèvre
authors: Muriel
authors: M
authors: Subirade
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism*; D001430:Bacteriocins / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D004134:Dimyristoylphosphatidylcholine / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism; D008954:Models, Biological; D000070017:Pediocins; D010715:Phosphatidylglycerols / Q000378:metabolism*; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D008051:Lipid Bilayers; D008563:Membrane Lipids; D000070017:Pediocins; D010715:Phosphatidylglycerols; C074288:pediocin PA-1; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine