An investigation of the effect of PVP-coated silver nanoparticles on the interaction between clonazepam and bovine serum albumin based on molecular dynamics simulations and molecular docking

Owing to the extensive application of silver nanoparticles (AgNPs) in medicine, the influence of AgNPs on the binding of clonazepam to bovine serum albumin (BSA) has been studied using ultraviolet-visible (UV–Vis), fluorescence, and circular dichroism (CD) spectroscopic methods. Detailed insights into the binding sites of clonazepam on the PVP-AgNP surface in the absence and presence of BSA have been obtained by carrying out molecular dynamics (MD) simulations and molecular docking analysis. UV–Vis results show that the interaction between BSA and AgNPs causes formation of BSA-AgNP complexes. CD studies imply that the formation of BSA-AgNP complexes is accompanied by conformational changes in the secondary structural level of the protein. The intrinsic fluorescence of BSA solution in the simultaneous presence of AgNPs and clonazepam shows that clonazepam interacts considerably more with BSA-AgNP complexes than with BSA. MD simulations results show that clonazepam molecules bind more to the PVP polymer film than to the bare Ag (0) atoms on the PVP-AgNP surface. Molecular docking analysis shows a binding affinity of −19.77 kJ/mol for BSA-AgNP complexes. Also, the results show that, although the IIA and IIIA domains in BSA play an important role in the docking of clonazepam with BSA, in BSA-AgNP complexes, clonazepam molecules bind to the bare Ag(0) atoms, and there is also the possibility of interaction between PVP and BSA via clonazepam.