Dengue is a potentially deadly disease with no effective drug. An in silico molecular docking was performed using Autodock
4.2.6 to investigate the molecular interactions between protease inhibitors, comprising antibiotic derivatives namely
doxycycline (3), rolitetracycline (5) and a non-steroidal anti-inflammatory drug (NSAID), meclofenamic acid (4), against
the NS2B-NS3 protease from dengue virus-2 (DENV-2). The non-competitive inhibitor (3) showed lower binding energy
(-5.15 kcal/mol) than the predicted competitive inhibitors 4 and 5 (-3.64 and -3.21 kcal/mol, respectively). Structural
analyses showed compound 3 that bound to a specific allosteric site, interacted with Lys74, a significant amino acid
residue bonded to one of the catalytic triad, Asp75. Compounds 4 and 5 showed direct binding with two of the catalytic
triad, His51 and Ser135, hence, predicted to be competitive inhibitors.