In vivo EPR on spin labeled colicin A reveals an oligomeric assembly of the pore-forming domain in E. coli membranes
Autor(en): | Dunkel, S. Pulagam, L. P. Steinhoff, H. -J. Klare, J. P. |
Stichwörter: | Chemistry; Chemistry, Physical; ELECTRON; HELICES; IA CHANNEL; MUTANTS; Physics; Physics, Atomic, Molecular & Chemical; PROTEINS; REDUCTION; RESONANCE; STATE; TOPOLOGY; TRANSLOCATION | Erscheinungsdatum: | 2015 | Herausgeber: | ROYAL SOC CHEMISTRY | Journal: | PHYSICAL CHEMISTRY CHEMICAL PHYSICS | Volumen: | 17 | Ausgabe: | 7 | Startseite: | 4875 | Seitenende: | 4878 | Zusammenfassung: | We report on the application of site-directed spin labeling (SDSL) and electron paramagnetic resonance (EPR) We report on the application of site-directed spin labeling (SDSL) and electron paramagnetic resonance (EPR) spectroscopy to study possible oligomerization of the bacterial toxin colicin A (ColA) upon membrane insertion in vitro and in vivo. We applied SDSL-EPR protocols and optimized experimental conditions to perform continuous wave EPR experiments and double electron-electron resonance distance measurements on intact Escherichia coli cells interacting with nitroxide spin-labeled ColA. Our data suggest that ColA forms dimers upon membrane insertion, thus explaining previously reported pore diameters of about 1 nm, which are unlikely to be formed by a single colicin A monomer. |
ISSN: | 14639076 | DOI: | 10.1039/c4cp05638h |
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