Discovery of antimicrobial compounds targeting bacterial type FAD synthetases

J Enzyme Inhib Med Chem. 2018 Dec;33(1):241-254. doi: 10.1080/14756366.2017.1411910.

Abstract

The increase of bacterial strains resistant to most of the available antibiotics shows a need to explore novel antibacterial targets to discover antimicrobial drugs. Bifunctional bacterial FAD synthetases (FADSs) synthesise the flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). These cofactors act in vital processes as part of flavoproteins, making FADS an essential enzyme. Bacterial FADSs are potential antibacterial targets because of differences to mammalian enzymes, particularly at the FAD producing site. We have optimised an activity-based high throughput screening assay targeting Corynebacterium ammoniagenes FADS (CaFADS) that identifies inhibitors of its different activities. We selected the three best high-performing inhibitors of the FMN:adenylyltransferase activity (FMNAT) and studied their inhibition mechanisms and binding properties. The specificity of the CaFADS hits was evaluated by studying also their effect on the Streptococcus pneumoniae FADS activities, envisaging differences that can be used to discover species-specific antibacterial drugs. The antimicrobial effect of these compounds was also evaluated on C. ammoniagenes, S. pneumoniae, and Mycobacterium tuberculosis cultures, finding hits with favourable antimicrobial properties.

Keywords: Bacterial FAD Synthetase; Streptococcus pneumoniae; drug discovery; high-throughput screening.

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Corynebacterium / drug effects
  • Corynebacterium / enzymology*
  • Dose-Response Relationship, Drug
  • Drug Discovery*
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Microbial Sensitivity Tests
  • Molecular Docking Simulation
  • Molecular Structure
  • Mycobacterium tuberculosis / drug effects
  • Nucleotidyltransferases / antagonists & inhibitors*
  • Nucleotidyltransferases / metabolism
  • Streptococcus pneumoniae / drug effects
  • Structure-Activity Relationship

Substances

  • Anti-Bacterial Agents
  • Enzyme Inhibitors
  • Nucleotidyltransferases
  • FMN adenylyltransferase

Grants and funding

This work has been supported by the Spanish Ministry of Economy, Industry and Competitiveness (MINEICO) [BIO2016–75183-P AEI/FEDER, UE to M.M.] and the Government of Aragón – FEDER [B18]. M.S. received a PhD Contract from Government of Aragón.