title: Beta-lactam screening by specific residues of the OmpF eyelet.
abstract: Beta-lactams use aqueous channels of porins to penetrate Gram-negative bacteria. The L3 loop of Escherichia coli OmpF porin is a key feature that actively contributes to both channel size and electrostatic properties. Acid residues D113, E117, and D121 are responsible for the negative part of the local electrostatic field on this loop. Two substitutions, D113A and D121A, located in the negatively charged cluster of the OmpF eyelet, increase the likelihood of producing bacteria susceptible to several beta-lactams. D113A substitution results in an increase in the ampicillin, cefoxitin, and ceftazidime susceptibility. Molecular modeling suggests that the charges harbored by the beta-lactam molecules interact with the charged residues located inside the porin eyelet.
authors.affiliation: GERCTOP UMR6178 CNRS, IFR48, Faculté de Pharmacie, Université de la Méditerranée, 13385 Marseille Cedex 05, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Vidal
authors.forename: Jérôme
authors.initials: J
authors.lastname: Bredin
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Pagès
authors.forename: Jacques
authors.initials: J
authors.lastname: Barbe
mesh_terms: D015169:Colony Count, Microbial; D004058:Diffusion; D021902:Enterobacter aerogenes / Q000187:drug effects / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation; D018272:Porins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D047090:beta-Lactams / Q000737:chemistry* / Q000494:pharmacology
chemical_list: C109237:OmpF protein; D018272:Porins; D047090:beta-Lactams