Targeting MurB from <i>Helicobacter pylori</i>: insights from virtual screening, molecular docking and molecular dynamics simulation

Helicobacter pylori is a gram-negative, helical-shaped bacteria found in the mucus lining of the stomach of humans responsible for causing sores or an ulcer. H. pylori is becoming a multi-drug resistant bacterium, which in turn demands the need for development of alternative treatment strategies for the proper management of diseases. The peptidoglycan biosynthesis pathway is critical for the synthesis of cell walls and for the survival of H. pylori. There are several crucial enzymes in this biosynthesis pathway which can act as significant drug targets against H. pylori. One of these important enzymes is UDP-N-acetylenolpyruvoylglucosamine reductase (MurB), which catalyses an important committed step of cell wall biosynthesis. In the present study, we performed a high throughput virtual screening using the Enamine HTSC library against the MurB enzyme. The molecules were also screened for druglike properties by ADME screening, toxicity, and tumorigenic nature, followed by MD simulations. We found that Z102621114_1 and Z228235240_1 ligand molecules can act as potential inhibitors of MurB protein. Our results suggest, these molecules may be able to meet the demand for novel antimicrobials to treat H. pylori medication resistance. The subsequent experimental investigations can increase their potential as a novel agents against H. pylori infections. Research highlightsHelicobacter pylori infects 50% of the Global population.Helicobacter pylori infection is associated with gastric cancer.MurB is a key drug target protein as it is responsible for cell wall synthesis.Z102621114_1 and Z228235240_1 were identified as potential inhibitors of MurB of Helicobacter pylori. Helicobacter pylori infects 50% of the Global population. Helicobacter pylori infection is associated with gastric cancer. MurB is a key drug target protein as it is responsible for cell wall synthesis. Z102621114_1 and Z228235240_1 were identified as potential inhibitors of MurB of Helicobacter pylori.</p

<i>In silico</i> strategies for identifying therapeutic candidates against <i>Acinetobacter baumannii</i>: spotlight on the UDP-N-acetylmuramoyl-L-alanine-D-glutamate:meso-diaminopimelate ligase (MurE)

The opportunistic bacterium Acinetobacter baumannii, which belongs to ESKAPE group of pathogenic bacteria, is leading cause of infections associated with gram-negative bacteria. Acinetobacter baumannii causes severe diseases, such as VAP (ventilator-associated pneumonia), meningitis, and UTI (urinary tract infections) among the nosocomial infections contracted in hospitals. The high infection rate and growing resistance to the vast array of antibiotics makes it paramount to look for new therapeutic strategies against this pathogen. The most promising therapeutic targets are the proteins involved in the synthesis of peptidoglycan which is chief component of bacterial cell wall, MurE is one of those enzymes and is responsible for the addition of one unit of meso-diaminopimelic acid (meso-A2pm) to the nucleotide precursor, UDPMurNAc-L-Ala-D-Glu, and aids in the formation of crosslinker pentapeptide chain. The three-dimensional structure of MurE was modelled using homology modelling technique and then vHTS was performed using this model against Approved Drug Library on DrugRep server using AutoDock Vina. Out of 500 drug molecules, two were selected based on estimated binding affinity, interaction pattern, interacting residues, etc. The selected drug molecules are DB12887 (Tazemetostat) and DB13879 (Glecaprevir). Then, MD simulations were performed on native MurE and its complexes with ligands to examine their dynamical behaviour, stability, integrity, compactness, and folding properties. The protein-ligand complexes were then subjected to binding free energy calculations using the MM/PBSA-based binding free energy analysis and the values are −109.788 ± 8.03 and −152.753 ± 11.98 kcal for MurE-DB12887 and MurE-DB13879 complex, respectively. All the analysis performed on MD trajectories for the complexes of these ligands with protein provided plenty of dependable evidences to consider these molecules for inhibition of MurE enzyme from A. baumannii. Communicated by Ramaswamy H. Sarma</p