Identification of Respiratory Syncytial Virus Fusion Protein Inhibitor: In silico Screening and Molecular Docking Approach

In young children, immunocompromised individuals, and elderly people, the respiratory syncytial virus (RSV) is the primary source of acute lower respiratory tract infection. Intervention with RSV-specific small-molecule antivirals may provide significant therapeutic potential. For virus entry, the RSV fusion protein (F) is crucial as it facilitates viral and hosts membrane fusion. To date, no approved vaccine or drug molecule is available to treat RSV. With this purpose, in the present study, virtual screening of a library of natural compounds against the active site of F protein was performed, followed by an in-depth molecular docking study of top-scored compounds. Selected hits ZINC8740013, ZINC4029781 and ZINC898642were found to strongly bind with RSV F protein relative to the other compounds as well as the control. The binding energy (BE) and inhibition constant for ‘ZINC8740013-RSV F’, ‘ZINC4029781-RSV F’, and ‘ZINC898642-RSVF’ complexes were found as ‘-7.8 kcal/mol and 63.27 µM’, ‘-7.7 kcal/mol and 19.04 µM’, and ‘-7.5 kcal/mol and 3.31 µM’, respectively. However, BE and inhibition constant of control (JNJ-53718678) with RSV F protein was found as -6.1 kcal/mol and 563.26 µM, respectively. Phe140 and Phe488 are the main interacting residues of RSV F protein with JNJ-53718678 and selected hit compounds. The finding of this study suggests that these hits can be utilized as the RSV Fprotein inhibitor to prevent the fusion of the viral envelope with the host cells. Further, bench work experiments are required to optimize these hit compounds as RSV Fprotein inhibitors.