Effect of membrane potential on pore formation by the antimicrobial peptide magainin 2 in lipid bilayers.

Autor: Rashid MMO; Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan., Moghal MMR; Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan., Billah MM; Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan., Hasan M; Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan., Yamazaki M; Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan; Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka 422-8529, Japan; Department of Physics, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan. Electronic address: yamazaki.masahito@shizuoka.ac.jp.
Jazyk: angličtina
Zdroj: Biochimica et biophysica acta. Biomembranes [Biochim Biophys Acta Biomembr] 2020 Oct 01; Vol. 1862 (10), pp. 183381. Date of Electronic Publication: 2020 Jun 03.
DOI: 10.1016/j.bbamem.2020.183381
Abstrakt: The effect of membrane potential on plasma membrane damage generated by antimicrobial peptides (AMPs) is an important, yet poorly characterized, process. Here, we studied the effect of membrane potential (φ m ) on pore formation by magainin 2 (Mag) in single giant unilamellar vesicles (GUVs) composed of dioleoylphosphatidylglycerol (DOPG)/dioleoylphosphatidylcholine (DOPC) membranes. Various membrane potentials in GUVs containing gramicidin A were generated as a result of K + concentration gradients. First, we examined Mag-generated membrane permeation of the water-soluble fluorescent probe calcein in single DOPG/DOPC-GUVs in the presence of membrane potential. The results indicate that the rate constant (k p ) of Mag-induced pore formation increased with increasing negative membrane potentials. Analysis of the rim intensity of single GUVs interacting with low concentrations of a fluorescent probe, carboxyfluorescein-labeled Mag (CF-Mag), using confocal laser scanning microscopy (CLSM) shows that the concentration of CF-Mag in the membrane greatly increased with negative membrane potentials. This indicates that the binding constant of CF-Mag to the membrane increased with more negative membrane potentials. To elucidate the location of Mag in a GUV with φ m during Mag-induced pore formation, we examined the interaction of Mag and a low concentration of a CF-Mag mixture with single GUVs containing the water-soluble fluorescent probe AF647 using CLSM. The data indicate that CF-Mag locates in the external leaflet of single GUVs until just before pore formation. Based on these data, we conclude that the increase in the surface concentration of Mag is one of the primary causes of the increase in k p with negative membrane potential.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: