Chlorpromazine and Amitriptyline Are Substrates and Inhibitors of the AcrB Multidrug Efflux Pump
| Autor: | Jack W Stone, Vito Ricci, Maria Laura Ciusa, Alasdair Ivens, Laura J. V. Piddock, Attilio Vittorio Vargiu, Paolo Ruggerone, Robert L Marshall, Chiara Fais, Elizabeth M Grimsey, Giuliano Malloci |
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| Rok vydání: | 2020 |
| Předmět: |
antibiotic resistance
Chlorpromazine Amitriptyline efflux pumps antipsychotic drugs Microbial Sensitivity Tests medicine.disease_cause Microbiology 03 medical and health sciences Antibiotic resistance Bacterial Proteins Drug Resistance Multiple Bacterial Virology Escherichia coli medicine Mode of action efflux pump inhibitors 030304 developmental biology 0303 health sciences biology 030306 microbiology Pseudomonas aeruginosa Chemistry Escherichia coli Proteins Membrane Transport Proteins Salmonella enterica AcrB Therapeutics and Prevention biology.organism_classification QR1-502 Anti-Bacterial Agents Acinetobacter baumannii Molecular Docking Simulation Multiple drug resistance Mechanism of action Biochemistry Mutation Efflux Multidrug Resistance-Associated Proteins medicine.symptom Protein Binding Research Article |
| Zdroj: | mBio mBio, Vol 11, Iss 3 (2020) mBio, Vol 11, Iss 3, p e00465-20 (2020) |
| ISSN: | 2150-7511 2161-2129 |
| DOI: | 10.1128/mbio.00465-20 |
| Popis: | Efflux pumps of the resistance nodulation-cell division (RND) superfamily are major contributors to multidrug resistance for most of the Gram-negative ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens. The development of inhibitors of these pumps would be highly desirable; however, several issues have thus far hindered all efforts at designing new efflux inhibitory compounds devoid of adverse effects. An alternative route to de novo design relies on the use of marketed drugs, for which side effects on human health have been already assessed. In this work, we provide experimental evidence that the antipsychotic drugs chlorpromazine and amitriptyline are inhibitors of the AcrB transporter, the engine of the major RND efflux pumps in Escherichia coli and Salmonella enterica serovar Typhimurium. Furthermore, in silico calculations have provided a molecular-level picture of the inhibition mechanism, allowing rationalization of experimental data and paving the way for similar studies with other classes of marketed compounds. Efflux is an important mechanism in Gram-negative bacteria conferring multidrug resistance. Inhibition of efflux is an encouraging strategy to restore the antibacterial activity of antibiotics. Chlorpromazine and amitriptyline have been shown to behave as efflux inhibitors. However, their mode of action is poorly understood. Exposure of Salmonella enterica serovar Typhimurium and Escherichia coli to chlorpromazine selected for mutations within genes encoding RamR and MarR, regulators of the multidrug tripartite efflux pump AcrAB-TolC. Further experiments with S. Typhimurium containing AcrB D408A (a nonfunctional efflux pump) and chlorpromazine or amitriptyline resulted in the reversion of the mutant acrB allele to the wild type. Together, this suggests these drugs are AcrB efflux substrates. Subsequent docking studies with AcrB from S. Typhimurium and E. coli, followed by molecular dynamics simulations and free energy calculations showed that chlorpromazine and amitriptyline bind at the hydrophobic trap, a preferred binding site for substrates and inhibitors within the distal binding pocket of AcrB. Based on these simulations, we suggest that chlorpromazine and amitriptyline inhibit AcrB-mediated efflux by interfering with substrate binding. Our findings provide evidence that these drugs are substrates and inhibitors of AcrB, yielding molecular details of their mechanism of action and informing drug discovery of new efflux inhibitors. |
| Databáze: | OpenAIRE |
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