1
|
Modak JK, Tikhomirova A, Gorrell RJ, Rahman MM, Kotsanas D, Korman TM, Garcia-Bustos J, Kwok T, Ferrero RL, Supuran CT, Roujeinikova A. Anti- Helicobacter pylori activity of ethoxzolamide. J Enzyme Inhib Med Chem 2019; 34:1660-1667. [PMID: 31530039 PMCID: PMC6759998 DOI: 10.1080/14756366.2019.1663416] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/16/2019] [Accepted: 08/23/2019] [Indexed: 01/23/2023] Open
Abstract
Ethoxzolamide (EZA), acetazolamide, and methazolamide are clinically used sulphonamide drugs designed to treat non-bacteria-related illnesses (e.g. glaucoma), but they also show antimicrobial activity against the gastric pathogen Helicobacter pylori. EZA showed the highest activity, and was effective against clinical isolates resistant to metronidazole, clarithromycin, and/or amoxicillin, suggesting that EZA kills H. pylori via mechanisms different from that of these antibiotics. The frequency of single-step spontaneous resistance acquisition by H. pylori was less than 5 × 10-9, showing that resistance to EZA does not develop easily. Resistance was associated with mutations in three genes, including the one that encodes undecaprenyl pyrophosphate synthase, a known target of sulphonamides. The data indicate that EZA impacts multiple targets in killing H. pylori. Our findings suggest that developing the approved anti-glaucoma drug EZA into a more effective anti-H. pylori agent may offer a faster and cost-effective route towards new antimicrobials with a novel mechanism of action.
Collapse
Affiliation(s)
- Joyanta K. Modak
- Department of Microbiology, Monash University, Clayton, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Alexandra Tikhomirova
- Department of Microbiology, Monash University, Clayton, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Rebecca J. Gorrell
- Department of Microbiology, Monash University, Clayton, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Mohammad M. Rahman
- Department of Microbiology, Monash University, Clayton, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Despina Kotsanas
- Monash Infectious Diseases, Monash University, Monash Health, Australia
| | - Tony M. Korman
- Monash Infectious Diseases, Monash University, Monash Health, Australia
| | - Jose Garcia-Bustos
- Department of Microbiology, Monash University, Clayton, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Terry Kwok
- Department of Microbiology, Monash University, Clayton, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Richard L. Ferrero
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia
| | - Claudiu T. Supuran
- Laboratorio di Chimica Bioinorganica, Polo Scientifico, Università degli Studi di Firenze, Sesto Fiorentino, Italy
- Neurofarba Department, Sezione di Scienze Farmaceutiche, Università degli Studi di Firenze, Sesto Fiorentino, Italy
| | - Anna Roujeinikova
- Department of Microbiology, Monash University, Clayton, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| |
Collapse
|
2
|
Structural Basis for the Inhibition of Helicobacter pylori α-Carbonic Anhydrase by Sulfonamides. PLoS One 2015; 10:e0127149. [PMID: 26010545 PMCID: PMC4444264 DOI: 10.1371/journal.pone.0127149] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 04/12/2015] [Indexed: 01/21/2023] Open
Abstract
Periplasmic α-carbonic anhydrase of Helicobacter pylori (HpαCA), an oncogenic bacterium in the human stomach, is essential for its acclimation to low pH. It catalyses the conversion of carbon dioxide to bicarbonate using Zn(II) as the cofactor. In H. pylori, Neisseria spp., Brucella suis and Streptococcus pneumoniae this enzyme is the target for sulfonamide antibacterial agents. We present structural analysis correlated with inhibition data, on the complexes of HpαCA with two pharmacological inhibitors of human carbonic anhydrases, acetazolamide and methazolamide. This analysis reveals that two sulfonamide oxygen atoms of the inhibitors are positioned proximal to the putative location of the oxygens of the CO2 substrate in the Michaelis complex, whilst the zinc-coordinating sulfonamide nitrogen occupies the position of the catalytic water molecule. The structures are consistent with acetazolamide acting as site-directed, nanomolar inhibitors of the enzyme by mimicking its reaction transition state. Additionally, inhibitor binding provides insights into the channel for substrate entry and product exit. This analysis has implications for the structure-based design of inhibitors of bacterial carbonic anhydrases.
Collapse
|
3
|
Marcus EA, Moshfegh AP, Sachs G, Scott DR. The periplasmic alpha-carbonic anhydrase activity of Helicobacter pylori is essential for acid acclimation. J Bacteriol 2005; 187:729-38. [PMID: 15629943 PMCID: PMC543530 DOI: 10.1128/jb.187.2.729-738.2005] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The role of the periplasmic alpha-carbonic anhydrase (alpha-CA) (HP1186) in acid acclimation of Helicobacter pylori was investigated. Urease and urea influx through UreI have been shown to be essential for gastric colonization and for acid survival in vitro. Intrabacterial urease generation of NH3 has a major role in regulation of periplasmic pH and inner membrane potential under acidic conditions, allowing adequate bioenergetics for survival and growth. Since alpha-CA catalyzes the conversion of CO2 to HCO3-, the role of CO2 in periplasmic buffering was studied using an alpha-CA deletion mutant and the CA inhibitor acetazolamide. Western analysis confirmed that alpha-CA was bound to the inner membrane. Immunoblots and PCR confirmed the absence of the enzyme and the gene in the alpha-CA knockout. In the mutant or in the presence of acetazolamide, there was an approximately 3 log10 decrease in acid survival. In acid, absence of alpha-CA activity decreased membrane integrity, as observed using membrane-permeant and -impermeant fluorescent DNA dyes. The increase in membrane potential and cytoplasmic buffering following urea addition to wild-type organisms in acid was absent in the alpha-CA knockout mutant and in the presence of acetazolamide, although UreI and urease remained fully functional. At low pH, the elevation of cytoplasmic and periplasmic pH with urea was abolished in the absence of alpha-CA activity. Hence, buffering of the periplasm to a pH consistent with viability depends not only on NH3 efflux from the cytoplasm but also on the conversion of CO2, produced by urease, to HCO3- by the periplasmic alpha-CA.
Collapse
Affiliation(s)
- Elizabeth A Marcus
- The Membrane Biology Laboratory, Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90073, USA
| | | | | | | |
Collapse
|
4
|
Moratal JM, Martinez-Ferrer MJ, Jiménez HR, Donaire A, Castells J, Salgado J. 1H NMR and UV-Vis spectroscopic characterization of sulfonamide complexes of nickel(II)-carbonic anhydrase. Resonance assignments based on NOE effects. J Inorg Biochem 1992; 45:231-43. [PMID: 1619400 DOI: 10.1016/0162-0134(92)84012-c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The binding of acetazolamide, p-fluorobenzensulfonamide, p-toluenesulfonamide, and sulfanilamide to nickel(II)-substituted carbonic anhydrase II has been studied by 1H NMR and electronic absorption spectroscopies. These inhibitors bind to the metal ion forming 1:1 complexes and their affinity constants were determined. The 1H NMR spectra of the formed complexes show a number of isotropically shifted signals corresponding to the histidine ligands. The complexes with benzene-sulfonamides gave rise to very similar 1H NMR spectra. The NMR data suggest that these aromatic sulfonamides bind to the metal ion altering its coordination sphere. In addition, from the temperature dependence of 1H NMR spectra of the p-fluorobenzenesulfonamide adduct, a conformational change is suggested. The T1 values of the meta-like protons of the coordinated histidines have been measured and resonance assignments based on NOE experiments were performed.
Collapse
Affiliation(s)
- J M Moratal
- Department of Inorganic Chemistry, University of Valencia, Spain
| | | | | | | | | | | |
Collapse
|
5
|
Coulson RA. Delayed protein digestion in the alligator following carbonic anhydrase inhibition. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1985; 82:43-7. [PMID: 2864210 DOI: 10.1016/0300-9629(85)90702-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Small alligators were injected with a carbonic anhydrase (CA) inhibitor (dichlorphenamide) and a day later they were fed large amounts of lean beef. The rate of protein digestion was determined and compared with that in controls fed the same amount. The controls began digestion at once, while in the CA-inhibited ones, digestion was blocked for over 10 hr. The inhibitor decreased gastric HCl production to one-third that in controls and delayed activation of pancreatic and intestinal proteases. After 15 hr, digestion began in the inhibited group and proceeded to completion. Once digestion began, further injections of the inhibitor could not block it. It seems that CA inhibition blocks digestion (for a time) by reducing HCl synthesis. NaHCO3 to neutralize the acid chyme in the intestine, was derived from that in the plasma.
Collapse
|