Synergism of Magainins is Not Coupled to the Formation of a Well-Defined Peptide Pore

PACHLER, M., Ivo KABELKA, R. LEBER, I. LETOFSKY-PAPST, K. LOHNER, Robert VÁCHA and G. PABST. Synergism of Magainins is Not Coupled to the Formation of a Well-Defined Peptide Pore. In 63rd Annual Meeting of the Biophysical-Society. 2019. ISSN 0006-3495. Available from: https://dx.doi.org/10.1016/j.bpj.2018.11.280.

Basic information

• Original name: Synergism of Magainins is Not Coupled to the Formation of a Well-Defined Peptide Pore
• Authors: PACHLER, M., Ivo KABELKA (203 Czech Republic, belonging to the institution), R. LEBER, I. LETOFSKY-PAPST, K. LOHNER, Robert VÁCHA (203 Czech Republic, guarantor, belonging to the institution) and G. PABST.
• Edition: 63rd Annual Meeting of the Biophysical-Society, 2019.

Other information

• Original language: English
• Type of outcome: Conference abstract
• Field of Study: 10403 Physical chemistry
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• Impact factor: Impact factor: 3.854
• RIV identification code: RIV/00216224:14740/19:00113469
• Organization unit: Central European Institute of Technology
• ISSN: 0006-3495
• Doi: http://dx.doi.org/10.1016/j.bpj.2018.11.280
• UT WoS: 000460779800219
• Keywords in English: Magainin
• Tags: rivok
• Tags: International impact

Abstract

We have studied the synergistic activity of PGLa and MG2a, two antimicrobial peptides secreted by the African clawed frog, on phosphatidylethanolamine/phosphatidylglycerol mimics of the inner membrane of Gram negative bacteria using an array of experimental and theoretical techniques. In particular, we correlated the peptides’ dye-releasing capabilities from large unilamellar vesicles with the induced structural changes on the microscopic to nanoscopic length scales combining small-angle X-ray and neutron scattering with transmission electron microscopy and molecular dynamics simulations. At low concentrations and in the absence of pronounced dye leakage we found that MG2a is aligned parallel to the membrane surface in the lipid’s headgroup region and causes a relocation of PGLa from the backbone region toward the polar surface. In the synergistic regime, i.e. at high concentrations, the peptides transformed the unilamellar vesicles into collapsed multilamellar liposomes with the peptides acting as spacers between the bilayers. In this case, the PGLa and MG2a do not exhibit strong cross-interactions and show the tendency to form fiber-like structures. PGLa and MG2a synergism in phosphatidylethanolamine/phosphatidylglycerol mixtures consequently does not involve the formation of a stable peptide pore within the bilayer as conceived previously.