INVESTIGADORES
PEREZ Pablo Fernando
congresos y reuniones científicas
Título:
On the antibacterial action of aurein 1.2 and maculatin 1.1 peptides over complex bilayers with differential glycolipid content. A multidisciplinary study using computational and experimental methods
Autor/es:
BALATTI GE; SZYMANOWSKI F.; HUGO A. A.; AMBROGGIO E.; GOMEZ ZAVAGLIA, A.; PÉREZ, P. F.; FIDELIO, G. D.; MARTINI, M. F. AND PICKHOLZ, M. A.
Reunión:
Congreso; XLVII Reunión Anual de la Sociedad Argentina de Biofísica.; 2018
Resumen:
The antimicrobial peptides (AMPs) are key molecules of the innate immune systemthat exert their action mainly against bacteria. It was suggested that AMPs act byincreasing the permeability of the membrane after an initial peptide-lipidinteraction. Among AMPs, the aurein and the maculatin exhibit a well-proven lyticactivity and, previously, we shed light about the molecular mechanism by whichthey damage different biomembranes by combined computational andexperimental approaches. We also found that the Lactobacillus delbrueckii subsp.lactis (CIDCA133) and the L. delbrueckii subsp. bulgaricus (CIDCA331) strains oflactic bacteria show differential susceptibility to the action of several AMPs,including aurein and maculatin.Considering that bilayer composition is a key aspect of the early peptide-lipidinteraction and that the resistant strain shows high amounts of glycolipids, wedefined a set of different model membranes and carried out extensive MolecularDynamics (MD) within the MARTINI coarse-grain (CG) force field. Since bothpeptides are helicoidal AMPs but they seem to act by different molecularmechanisms, the aim was to understand how the lipid composition is related withthe resistance to the action of that kind of peptides.The results show a capability of both peptides to affect membrane bilayers, butthe different membranes are differentially affected. In effect, we found a strongcorrelation between the proportion of glycolipids in the membrane and the abilityto keep the membrane integrity against the AMP action. In addition, and as wepointed in previous works, maculatin can induce membrane curvature in thebilayers, despite the glycolipid presence. Each model membrane shows differentialmolecular behavior with the AMP molecules, and the use of CG simulationssupported by experimental techniques can help to elucidate the specific molecularfactors that allow certain bilayer configurations to resist or diminish the effects ofAMPs against them.