Show simple item record

dc.contributor.authorCama, Jehangiren
dc.contributor.authorBajaj, Harshaen
dc.contributor.authorPagliara, Stefanoen
dc.contributor.authorMaier, Theresaen
dc.contributor.authorBraun, Yvonneen
dc.contributor.authorWinterhalter, Mathiasen
dc.contributor.authorKeyser, Ulrichen
dc.date.accessioned2016-01-19T13:37:14Z
dc.date.available2016-01-19T13:37:14Z
dc.date.issued2015-10-19en
dc.identifier.citationJournal of the American Chemical Society 2015, 137(43): 13836-13843. doi:10.1021/jacs.5b08960en
dc.identifier.issn0002-7863
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/253346
dc.description.abstractDecreased drug accumulation is a common cause of antibiotic resistance in microorganisms. However, there are few reliable general techniques capable of quantifying drug uptake through bacterial membranes. We present a semiquantitative optofluidic assay for studying the uptake of autofluorescent drug molecules in single liposomes. We studied the effect of the Escherichia coli outer membrane channel OmpF on the accumulation of the fluoroquinolone antibiotic, norfloxacin, in proteoliposomes. Measurements were performed at pH 5 and pH 7, corresponding to two different charge states of norfloxacin that bacteria are likely to encounter in the human gastrointestinal tract. At both pH values, the porins significantly enhance drug permeation across the proteoliposome membranes. At pH 5, where norfloxacin permeability across pure phospholipid membranes is low, the porins increase drug permeability by 50-fold on average. We estimate a flux of about 10 norfloxacin molecules per second per OmpF trimer in the presence of a 1 mM concentration gradient of norfloxacin. We also performed single channel electrophysiology measurements and found that the application of transmembrane voltages causes an electric field driven uptake in addition to concentration driven diffusion. We use our results to propose a physical mechanism for the pH mediated change in bacterial susceptibility to fluoroquinolone antibiotics.
dc.description.sponsorshipThis work was supported by a European Research Council (ERC) Grant (261101 Passmembrane) to UFK. JC acknowledges support from an Internal Graduate Studentship, Trinity College, Cambridge, and a Research Studentship from the Cambridge Philosophical Society. SP was supported by the Leverhulme Trust through an Early Career Fellowship. TM acknowledges support from the Konrad-Adenauer Foundation and the German National Merit Foundation. HB, YB and MW are part of the TRANSLOCATION consortium and have received support from the Innovative Medicines Joint Undertaking under grant agreement 115525, the European Union’s seventh framework program (FP7/2007-2013), and European Federation of Pharmaceutical Industries and Associates companies in-kind contribution. We thank Avelino Javer for help with the MATLAB scripts and Catalin Chimerel for helpful discussions.
dc.languageEnglishen
dc.language.isoenen
dc.publisherACS
dc.titleQuantification of Fluoroquinolone Uptake through the Outer Membrane Channel OmpF of Escherichia colien
dc.typeArticle
dc.description.versionThis is the author accepted manuscript. The final version is available from ACS via http://dx.doi.org/10.1021/jacs.5b08960en
prism.publicationDate2015en
prism.publicationNameJournal of the American Chemical Societyen
dc.rioxxterms.funderERC
rioxxterms.versionofrecord10.1021/jacs.5b08960en
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserveden
rioxxterms.licenseref.startdate2015-10-19en
dc.contributor.orcidCama, Jehangir [0000-0002-5982-1941]
dc.contributor.orcidKeyser, Ulrich [0000-0003-3188-5414]
dc.identifier.eissn1520-5126
rioxxterms.typeJournal Article/Reviewen
pubs.funder-project-idEuropean Research Council (261101)
rioxxterms.freetoread.startdate2016-10-19


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record