2.7 In-silico molecular docking
In-silico molecular docking of OST was performed using catalytic subunits, STT3A and STT3B. The AlphaFold structures of STT3A (AF-P46977-F1) and STT3B (AF-Q8TCJ2-F1) were retrieved from UniProt (24). A library of 89 potential FDA approved drug candidates was prepared by downloading their 3D structure for PubChem database (25). NGI-1, a known OST inhibitor was used as control to set the threshold for the binding energy and to determine the active sites of the proteins. Energy minimization of ligands was performed using open babel and Autodock Vina (Version 1.1.2) (26) of PyRx software was used to perform docking with exhaustiveness value set to 50. The out.pdbqt files generated after the molecular docking were split into individual poses using vina split command and the pose with lowest binding energy was used for post docking analysis. PyMOL (Version 2.5.4) and Discovery Studio Visualizer Software (Version 4.0) was used to visualize the docked structures and binding interactions were identified using protein-ligand interaction profiler (PLIP) server (27).