Docking of phosphonate and trehalose analog inhibitors into M. tuberculosis mycolyltransferase Ag85C: Comparison of the two scoring fitness functions GoldScore and ChemScore, in the GOLD software

The Ag85 family enzymes are responsible for the synthesis of cell wall components in mycobacterial species. Inhibitors to these enzymes are potential antimycobacterial agents. We have carried out the docking of phoshonate and trehalose analog inhibitors into the three dimensional structure of mycolyltransferase enzyme, Ag85C of M. tuberculosis using the GOLD software. The inhibitor binding positions and affinity were evaluated using both the scoring fitness functions- GoldScore and ChemScore. We observed that the inhibitor binding position identified using the GoldScore was marginally better than the ChemScore. A qualitative agreement between the reported experimental biological activities (IC50) and the GoldScore was observed. We identified that amino acid residues Arg541, Trp762 are important for inhibitor recognition via hydrogen bonding interactions. This information can be exploited to design Ag85C specific inhibitors.