In silico Discovery of a New Potent Inhibitor for Sterol 14-alpha Demethylase as a Promising Antifungal Drug against Aspergillus fumigatus Infection

Abstract

Aspergillus fumigatus is a dangerous opportunistic pathogen that causes severe consequences for human beings when its conidia are inhaled. Several inhibitory drugs have recently been suggested to eradicate these fungi by inhibiting the cytochrome P450 sterol 14-alpha demethylase B (CYP51B). These drugs are designed to exhibit high specificity to the heme that is incorporated in the active site of this enzyme. Though effective binding with heme can be achieved, administration of these drugs can be accompanied by variable risks to the user’s health. Series of in silico screenings were conducted to find out more eligible drug-like compounds to inhibit CYP51B-heme with fewer side effects on patients. Using stringent ZINCPharmer restrictions, seventeen compounds were found to have efficient binding to the heme group of CYP51B. Their effectiveness against CYP51B was tested using molecular docking, drug-likeness prediction, and molecular dynamics (MD) simulation. One compound (ZINC000015774018 or molecule-8) was found to inhibit the heme group with better drug-likeness than that found in the other sixteen drug-like compounds. MD simulations showed that this ligand introduced stabilized interactions with the targeted protein upon interacting with its heme and amino acid residues. Thus it may be used as a potent antifungal inhibitor against A. fumigatus.