Evaluation of the combination mode of azoles antifungal inhibitors with CACYP51 and the influence of Site-directed mutation

J Mol Graph Model. 2017 May:73:157-165. doi: 10.1016/j.jmgm.2017.02.009. Epub 2017 Feb 21.

Abstract

14α-demethylase (CYP51) is an essential metabolic enzyme for fungal survival and has been considered as an interesting target for the development of new antifungal inhibitors. Azoles antifungal inhibitors in the treatment of fungal diseases are good candidates via the interaction with the target enzyme CYP51 of fungus. In the study, we constructed the homology model for Candida albicans CYP51 (CACYP51) and analyzed the active site. In order to better understand the structural characteristics of azoles inhibitors and combination mode, the common feature pharmacophore model and the molecular docking were performed. The results suggest that the azoles inhibitors consist of three chemical features: the aromatic groups, phenyl groups and the azoles groups. The aromatic groups of inhibitors occupy the upper of active pocket, the phenyl groups and azoles groups occupy the bottom of active pocket. Further validation studies found these amino acid residues Tyr118, His310 and Ser378 play an important role in the substrate binding, and these amino acid residues with site-directed mutation will weaken the combining ability of the inhibitors.

Keywords: Azoles CACYP51 inhibitors; Homology model; Molecular docking; Site-directed mutation.

MeSH terms

  • Amino Acid Sequence
  • Antifungal Agents / chemistry
  • Antifungal Agents / pharmacology*
  • Azoles / chemistry
  • Azoles / pharmacology*
  • Candida albicans / drug effects
  • Candida albicans / enzymology*
  • Catalytic Domain
  • Cytochrome P-450 Enzyme Inhibitors / chemistry
  • Cytochrome P-450 Enzyme Inhibitors / pharmacology*
  • Cytochrome P450 Family 51 / chemistry
  • Cytochrome P450 Family 51 / genetics*
  • Drug Resistance, Fungal
  • Drug Synergism
  • Fungal Proteins / chemistry
  • Fungal Proteins / pharmacology*
  • Hydrophobic and Hydrophilic Interactions
  • Molecular Docking Simulation
  • Mutagenesis, Site-Directed*
  • Mutation
  • Sequence Alignment
  • Structural Homology, Protein

Substances

  • Antifungal Agents
  • Azoles
  • Cytochrome P-450 Enzyme Inhibitors
  • Fungal Proteins
  • Cytochrome P450 Family 51