title: Characterization of the kinetics and mechanisms of inhibition of drugs interacting with the S. cerevisiae multidrug resistance pumps Pdr5p and Snq2p.
abstract: We have developed a novel screening method that measures the kinetics and potencies of inhibitors of the yeast multidrug resistance pumps Pdr5p and Snq2p. The assay uses the potentiometric fluorescent probe diS-C(3)(3) (as a benchmark substrate of both pumps) to distinguish drugs with minimal effects on plasma membrane potential as a marker of side-effects on membrane function and integrity. Using FK506, its structural analog rapamycin and enniatin B, we showed that our assay can also be used to determine the minimum drug concentration causing an immediate inhibitory effect and to compare the inhibitory potencies of the drug on the two pumps. We found that the protonophore CCCP effectively inhibits the transport of diS-C(3)(3) by both pumps and confirmed the activation of membrane H(+)-ATPase by CCCP.
authors.affiliation: Charles University, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
authors.forename: Tomás
authors.initials: T
authors.lastname: Hendrych
authors.forename: Marie
authors.initials: M
authors.lastname: Kodedová
authors.forename: Karel
authors.initials: K
authors.lastname: Sigler
authors.forename: Dana
authors.initials: D
authors.lastname: Gásková
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000737:chemistry*; D002232:Carbocyanines / Q000494:pharmacology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D007700:Kinetics; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D016559:Tacrolimus / Q000494:pharmacology; D015091:beta-Alanine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: C091791:3,3'-dipropylthiacarbocyanine; D018528:ATP-Binding Cassette Transporters; D002232:Carbocyanines; C092438:PDR5 protein, S cerevisiae; C101797:SNQ2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C501402:undecyl 3-(dimethylamino)propionate; D015091:beta-Alanine; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D016559:Tacrolimus