Journal of Molecular Modeling

, Volume 17, Issue 4, pp 869–877

Relationship between mutation of serine residue at 315th position in M. tuberculosis catalase-peroxidase enzyme and Isoniazid susceptibility: An in silico analysis

  • Rituraj Purohit
  • Vidya Rajendran
  • Rao Sethumadhavan
Original Paper

DOI: 10.1007/s00894-010-0785-6

Cite this article as:
Purohit, R., Rajendran, V. & Sethumadhavan, R. J Mol Model (2011) 17: 869. doi:10.1007/s00894-010-0785-6

Abstract

Remarkable advances have been made in the drug therapy of tuberculosis. However much remains to be learned about the molecular and structural basis of drug resistance in Mycobacterium tuberculosis. It is known that, activation of Isoniazid (INH) is mediated by Mycobacterium tuberculosis catalase-peroxidase (MtBKatG) and mutation at position 315 (serine to threonine) leads to resistance. We have conducted studies on the drug resistance through docking and binding analysis supported by time-scale (∼1000 ps) and unrestrained all-atom molecular dynamics simulations of wild and mutant MtBKatG. The study showed conformational changes of binding residues. Mutant (S315T) showed high docking score and INH binding affinity as compared to wild enzyme. In molecular dynamics simulation, mutant enzyme exhibited less structure fluctuation at INH binding residues and more degree of fluctuation at C-terminal domain compared to wild enzyme. Our computational studies and data endorse that MtBKatG mutation (S315T) decrease the flexibility of binding residues and made them rigid by altering the conformational changes, in turn it hampers the INH activity. We ascertain from this work that, this study on structural mechanism of resistance development in Mycobacterium tuberculosis would lead to new therapeutics based on the result obtained in this study.

Keywords

Binding affinityCatalase-peroxidaseDockingIsoniazidMolecular dynamic simulationResistance mutationSolvent accessibility

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Rituraj Purohit
    • 1
  • Vidya Rajendran
    • 1
  • Rao Sethumadhavan
    • 1
  1. 1.School of Bio Sciences and Technology (SBST), Bioinformatics DivisionVellore Institute of Technology UniversityVelloreIndia