The gram-negative bacterium Escherichia coli as a model for testing the effect of carbonic anhydrase inhibition on bacterial growth

Abstract

Carbonic anhydrases, catalysing the reversible CO₂ hydration reaction, contribute in all living organisms to the maintenance of stable metabolic functions depending on intracellular concentrations of carbon dioxide, bicarbonate, and protons. Recent studies have examined how CAs affect bacterial lifecycle, considering these enzymes druggable targets due to interference with their activities by using inhibitors or activators. Here, we propose Escherichia coli cells as a model for testing the effect of acetazolamide (AZA), a potent CA inhibitor, on bacterial survival by evaluating E. coli growth through its glucose consumption. AZA, at concentrations higher than 31.2 µg/mL, was able to impair E. coli growth and glucose uptake. AZA is a good inhibitor of the two recombinant E. coli CAs, the β-CA CynT2, and the γ-CA EcoCAγ, with KIs of 227 and 248 nM, respectively. This study provides a proof-of-concept, low-cost method for identifying effective CA inhibitors capable of impairing bacterial metabolism.

Keywords:

• Carbonic anhydrases
• sulphonamide
• inhibitor
• phenol-sulphuric acid assay
• glucose consumption
• bacterial growth
• microorganism lifecycle

Acknowledgements

The authors are grateful to Chiara Nobile, Valentina Brasiello and Marco Petruzziello for technical assistance.

Disclosure statement

CT Supuran is Editor-in-Chief of the Journal of Enzyme Inhibition and Medicinal Chemistry and he was not involved in the assessment, peer review, or decision-making process of this paper. The authors have no relevant affiliations of financial involvement with any organisation or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. C Capasso and CT Supuran thank the Italian Ministry for University and Research (MIUR), for the project FISR2019_04819 BacCAD with which this research was funded.

Additional information

Funding

The research program was funded by the Italian Ministry for University and Research (MIUR), project FISR2019_04819 BacCAD.