Binding of Pediocin PA-1 with Anionic Lipid Induces Model Membrane Destabilization |
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| Authors: | Hlne Gaussier Thierry Lefvre and Muriel Subirade |
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| Affiliation: | Hélène Gaussier, Thierry Lefèvre, and Muriel Subirade |
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| 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 D2O 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 νs(CH2) and carbonyl ν(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. |
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