Interaction of Streptomyces sp. VITSTK7 compounds with selected antifungal drug target enzymes by in silico molecular docking studies

Antifungal drugs are inhibitors either of fungal cell wall biosynthesis or essential reaction steps of fungal metabolic pathways. In silico studies have proved to be very effective on screening small molecules to be used as drugs and identifying essential reactions and pathways as targets. The aim of the present study was to predict the interactions of compounds present in the ethyl acetate extract of Streptomyces sp. VITSTK7 against selected fungal drug target enzymes. The ethyl acetate extract of the isolate showed significant anti-Aspergillus activity against the selected Aspergillus pathogens. Presence of the three compounds (C22H37NO7, C17H24N4O6 and C24H28N2O5) in the extract was identified by GC-MS spectra and matched with reference compounds available in the MS spectra library, NIST (National Institute for Standards and Technology). These compounds were analysed for the interaction with five selected fungal target proteins 1AFR, 1EA1, 1LKP, 1ZHX and 3PD73i3E. Docking was done using Patch dock beta 1.3 version and analysed by pymol 1.3 version. The tested compounds C22H37NO7, C17H24N4O6 and C24H28N2O5 showed least binding energy of -254.64 kcal/mol, -248.71 kcal/mol and -338.57 kcal/mol respectively with 1ZHX. The result of this study revealed that all the three compounds from the strain had higher interaction with 1ZHX protein than with the other proteins. It shows that this strain could be the promising source for the antifungal drug.