Journal Article

PUBDB-2019-00187

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Unravelling a Mechanism of Action for a Cecropin A-Melittin Hybrid Antimicrobial Peptide: The Induced Formation of Multilamellar Lipid Stacks

Silva, T. ; Claro, B. ; Silva, B. F. B. ; Vale, N. ; Gomes, P. ; Gomes, M. S. ; Funari, S. d. S.DESY* ; Teixeira, J. ; Uhríková, D. (Corresponding author)Extern* ; Bastos, M. (Corresponding author)Extern*

2018
ACS Publ. Washington, DC

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Please use a persistent id in citations: doi:10.1021/acs.langmuir.7b03639  doi:10.3204/PUBDB-2019-00187

Abstract: An understanding of the mechanism of action of antimicrobial peptides is fundamental to the development of new and more active antibiotics. In the present work, we use a wide range of techniques (SANS, SAXD, DSC, ITC, CD, and confocal and electron microscopy) in order to fully characterize the interaction of a cecropin A-melittin hybrid antimicrobial peptide, CA(1-7)M(2-9), of known antimicrobial activity, with a bacterial model membrane of POPE/POPG in an effort to unravel its mechanism of action. We found that CA(1-7)M(2-9) disrupts the vesicles, inducing membrane condensation and forming an onionlike structure of multilamellar stacks, held together by the intercalated peptides. SANS and SAXD revealed changes induced by the peptide in the lipid bilayer thickness and the bilayer stiffening in a tightly packed liquid-crystalline lamellar phase. The analysis of the observed abrupt changes in the repeat distance upon the phase transition to the gel state suggests the formation of an L$_γ$ phase. To the extent of our knowledge, this is the first time that the $_γ$ phase is identified as part of the mechanism of action of antimicrobial peptides. The energetics of interaction depends on temperature, and ITC results indicate that CA(1-7)M(2-9) interacts with the outer leaflet. This further supports the idea of a surface interaction that leads to membrane condensation and not to pore formation. As a result, we propose that this peptide exerts its antimicrobial action against bacteria through extensive membrane disruption that leads to cell death.

Note: © American Chemical Society

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Contributing Institute(s):

1. DOOR-User (DOOR)
2. PETRA III Extension (FS-PEX)

Research Program(s):

1. 6215 - Soft Matter, Health and Life Sciences (POF3-621) (POF3-621)

Experiment(s):

1. DORIS Beamline A2 (DORIS III)

Appears in the scientific report 2018

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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