title: Permeation of antibiotics through Escherichia coli OmpF and OmpC porins: screening for influx on a single-molecule level.
abstract: A chip-based automated patch-clamp technique provides an attractive biophysical tool to quantify solute permeation through membrane channels. Proteo-giant unilamellar vesicles (proteo-GUVs) were used to form a stable lipid bilayer across a micrometer-sized hole. Because of the small size and hence low capacitance of the bilayer, single-channel recordings were achieved with very low background noise. The latter allowed the characterization of the influx of 2 major classes of antibiotics-cephalosporins and fluoroquinolones-through the major Escherichia coli porins OmpF and OmpC. Analyzing the ion current fluctuations in the presence of antibiotics revealed transport properties that allowed the authors to determine the mode of permeation. The chip-based setup allows rapid solution exchange and efficient quantification of antibiotic permeation through bacterial porins on a single-molecule level.
authors.affiliation: School of Engineering and Science, Jacobs University Bremen, Bremen, Germany.
authors.forename: Kozhinjampara R
authors.initials: KR
authors.lastname: Mahendran
authors.forename: Mohamed
authors.initials: M
authors.lastname: Kreir
authors.forename: Helge
authors.initials: H
authors.lastname: Weingart
authors.forename: Niels
authors.initials: N
authors.lastname: Fertig
authors.forename: Mathias
authors.initials: M
authors.lastname: Winterhalter
mesh_terms: D002463:Cell Membrane Permeability; D002511:Cephalosporins / Q000378:metabolism*; D004926:Escherichia coli / Q000166:cytology* / Q000378:metabolism*; D024841:Fluoroquinolones / Q000378:metabolism*; D017136:Ion Transport; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism; D018408:Patch-Clamp Techniques / Q000379:methods*; D018272:Porins / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary
chemical_list: D002511:Cephalosporins; D024841:Fluoroquinolones; D008051:Lipid Bilayers; C113724:OmpC protein; C109237:OmpF protein; D018272:Porins