Molecular docking study of sappan wood extract to inhibit PBP2A enzyme on methicillin-resistant Staphylococcus aureus (MRSA)

Background: PBP2a is a type of penicillin-binding proteins (PBPs) that cause resistivity in methicillin-resistant Staphylococcus aureus (MRSA) from β-lactam antibiotics. MRSA susceptible with cefttobiprole (fifth generation of cephalosporin as an anti-MRSA agent) which inhibits PBP2a and stops its growth. Contrary to its efficacy, ceftobiprole causes taste disturbance more than any other cephalosporins; furthermore, its mechanism is unknown. This study aims to explore an in silico study of a natural compound, which serves as a potential alternative to overcome MRSA with minimum adverse side effects. Methods: A molecular docking study was performed using Molegro Virtual Docker version 5.5. Brazilin and proto-sappanins A–E are phytochemical compounds contained in sappan wood extract and are docked into the binding site of PBP2a (Protein Data Bank: ID 4DKI). Results: Brazilin and proto-sappanins A–E have some interaction with Ser 403 amino acid residue which is an important interaction to inhibit PBP2a protein. The result of the molecular docking study showed that the MolDock score of proto-sappanins D and E is lower than that of methicillin but higher than that of its native ligand (ceftobiprole). Conclusions: The results of this study suggest that proto-sappanins D and E have an excellent potential activity as an alternative to ceftobiprole in limiting MRSA growth through PBP2A enzyme inhibition