The inhibitory activity of Ruxolitinib against COVID-19 major protease enzyme and SARS CoV-2 spike glycoprotein: A molecular docking study

Ruxolitinib (C17H18N6) is a Janus kinase (JAK) inhibitor that inhibits JAK1, JAK2, and JAK3 and with its tyrosine kinase inhibitor function It is the first drug approved for use in the treatment of myelofibrosis. The possible conformations of the ruxolitinib molecule were searched using PM3 technique and the Spartan06 software. The estimated molecular energies of the Ruxolitinib conformers, obtained by the variations in dihedral angles, were compared, and the most stable conformer was determined. To enlighten the inhibitory activity of Ruxolitinib agaist the apo (PDB ID: 6M03) and holo (PDB ID: 6LU7) forms of the main protease enzyme (Mpro) of COVID-19 and the SARSCoV-2 spike glycoprotein (PDB ID: 6VXX), molecular docking simulations were performed. The binding affinities and binding modes were determined. The binding free energies of ruxolitinib and 6M03, 6LU7, 6VXX targets calculated by the combination of Molecular Mechanics/Generalized Born Surface Area (MMGBSA) and Molecular Mechanics/Poisson-Boltzmann Surface Area (MM-PBSA) methods {MM/PB(GB)SA approach}, were found to be -22.24, -19.96 and -22.44 kcal/mol, respectively.