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²H-NMR and MD Simulations Reveal Membrane-Bound Conformation of Magainin 2 and Its Synergy with PGLa

Strandberg, Erik 1; Horn, Diana 2; Reißer, Sabine 1,3; Zerweck, Jonathan 2; Wadhwani, Parvesh 1; Ulrich, Anne S. 1,2
1 Institut für Biologische Grenzflächen (IBG), Karlsruher Institut für Technologie (KIT)
2 Institut für Organische Chemie (IOC), Karlsruher Institut für Technologie (KIT)
3 Institut für Physikalische Chemie (IPC), Karlsruher Institut für Technologie (KIT)

Abstract (englisch):

Magainin 2 (MAG2) and PGLa are two α-helical antimicrobial peptides found in the skin of the African frog Xenopus laevis. They act by permeabilizing bacterial membranes and exhibit an exemplary synergism. Here, we determined the detailed molecular alignment and dynamical behavior of MAG2 in oriented lipid bilayers by using 2H-NMR on Ala-d3-labeled peptides, which yielded orientation-dependent quadrupolar splittings of the labels. The amphiphilic MAG2 helix was found to lie flat on the membrane surface in 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC)/1,2-dimyristoyl-sn-glycero-3-phosphatidylglycerol (DMPG) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG), as expected, with a tilt angle close to 90°. This orientation fits well with all-atom molecular-dynamics simulations of MAG2 performed in DMPC and DMPC/DMPG. In the presence of an equimolar amount of PGLa, the NMR analysis showed that MAG2 becames tilted at an angle of 120°, and its azimuthal rotation angle also changes. Since this interaction was found to occur in a concentration range where the peptides per se do not interact with their own type, we propose that MAG2 forms a stable heterodimer with PGLa. ... mehr


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Originalveröffentlichung
DOI: 10.1016/j.bpj.2016.10.012
Scopus
Zitationen: 27
Web of Science
Zitationen: 25
Dimensions
Zitationen: 30
Zugehörige Institution(en) am KIT Institut für Biologische Grenzflächen (IBG)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2016
Sprache Englisch
Identifikator ISSN: 0006-3495, 1542-0086
KITopen-ID: 1000062260
HGF-Programm 47.02.02 (POF III, LK 01) Zellpopul.auf Biofunk.Oberflächen IBG-2
Erschienen in Biophysical journal
Verlag Biophysical Society
Band 111
Heft 10
Seiten 2149-2161
Vorab online veröffentlicht am 15.11.2016
Externe Relationen Abstract/Volltext
Nachgewiesen in Scopus
Web of Science
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