Deciphering Campylobacter jejuni DsbA1 protein dynamics in the presence of anti-virulent compounds: a multi-pronged computer-aided approach

Abstract

The current study aims to evaluate Asinex library compounds against Campylobacter jejuni DsbA1 protein, a thiol disulfide oxidoreductase enzyme that plays a major role in the oxidative folding of bacterial virulence proteins, making it a promising anti-viral drug target. By employing several techniques of computer-aided drug design, BDC25697459, BDD33601083, and BDC30129064 were identified with binding energy scores of −8.8 kcal/mol, −8.8 kcal/mol, and −8.3 kcal/mol, respectively. However, the control molecule, tetraethylene glycol, exhibited a binding energy score of −7.0 kcal/mol. The control, BDD33601083, and BDC30129064 were unveiled to bind the same co-crystallized binding site (pocket 1), while BDC25697459 interacted with a new binding pocket (pocket 2) adjacent to the control binding region. The molecular dynamics simulation showed that complexes exhibit stable dynamics without significant global or residue-level fluctuations. The average RMSD values were in the range of 2.07 Å–2.45 Å. Similarly, mean RMSF was recorded between 1.30 and 1.42 Å. The C. jejuni DsbA1 was also observed as compact in the presence of the compounds, showing a mean RoG value in the range of 16.42 Å–16.55 Å. In terms of MM/PBSA binding energy, the BDC30129064 complex was ranked top with −44.88 ± 4.14 kcal/mol, whereas the positive control molecule exhibited −22.22 ± 3.33 kcal/mol. From a pharmacokinetic perspective, the compounds are suitable candidates for clinical trial investigation. Preliminary computational analysis of these virtual hits indicates that these compounds have a low potential for ADME and toxicity-associated liabilities. In summary, the compounds displayed a high affinity for the C. jejuni DsbA1 protein, indicating potential efficacy that requires further investigation. Communicated by Ramaswamy H. Sarma