Structure-Based Rational Design of Novel Inhibitors Against Fructose-1,6-Bisphosphate Aldolase from Candida albicans

J Chem Inf Model. 2017 Jun 26;57(6):1426-1438. doi: 10.1021/acs.jcim.6b00763. Epub 2017 May 16.

Abstract

Class II fructose-1,6-bisphosphate aldolases (FBA-II) are attractive new targets for the discovery of drugs to combat invasive fungal infection, because they are absent in animals and higher plants. Although several FBA-II inhibitors have been reported, none of these inhibitors exhibit antifungal effect so far. In this study, several novel inhibitors of FBA-II from C. albicans (Ca-FBA-II) with potent antifungal effects were rationally designed by jointly using a specific protocols of molecular docking-based virtual screening, accurate binding-conformation evaluation strategy, synthesis and enzymatic assays. The enzymatic assays reveal that the compounds 3c, 3e-g, 3j and 3k exhibit high inhibitory activity against Ca-FBA-II (IC50 < 10 μM), and the most potential inhibitor is 3g, with IC50 value of 2.7 μM. Importantly, the compounds 3f, 3g, and 3l possess not only high inhibitions against Ca-FBA-II, but also moderate antifungal activities against C. glabrata (MIC80 = 4-64 μg/mL). The compounds 3g, 3l, and 3k in combination with fluconazole (8 μg/mL) displayed significantly synergistic antifungal activities (MIC80 < 0.0625 μg/mL) against resistant Candida strains, which are resistant to azoles drugs. The probable binding modes between 3g and the active site of Ca-FBA-II have been proposed by using the DOX (docking, ONIOM, and XO) strategy. To our knowledge, no FBA-II inhibitors with antifungal activities against wild type and resistant strains from Candida were reported previously. The positive results suggest that the strategy adopted in this study are a promising method for the discovery of novel drugs against azole-resistant fungal pathogens in the future.

MeSH terms

  • Antifungal Agents / chemistry*
  • Antifungal Agents / pharmacology*
  • Candida albicans / drug effects
  • Candida albicans / enzymology*
  • Drug Design*
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / pharmacology*
  • Fructose-Bisphosphate Aldolase / antagonists & inhibitors*
  • Fructose-Bisphosphate Aldolase / chemistry
  • Fructose-Bisphosphate Aldolase / metabolism
  • Fructosediphosphates / metabolism
  • Microbial Sensitivity Tests
  • Molecular Dynamics Simulation

Substances

  • Antifungal Agents
  • Enzyme Inhibitors
  • Fructosediphosphates
  • Fructose-Bisphosphate Aldolase
  • fructose-1,6-diphosphate