Adducts of bovine serum albumin and binuclear nitrosyl iron complex with thiosulfate ligands: a molecular docking and quantum chemical study

A molecular docking study aimed at shedding light on the binding mechanisms of a nitrosyl iron complex to bovine serum albumin (BSA) revealed three possible binding sites. Main types of bonds were established. The complex—BSA binding energies at different sites were determined using the AutoDockTools program and from QTAIM analysis. Docking with inclusion of water molecules led to shielding of one binding site (only two binding sites remain) and to a better agreement between the binding energies obtained by two different methods. Electronic spectra of the resulting molecular complexes were simulated in terms of the time-dependent density functional theory (TDDFT). The changes in the experimental spectrum as well as stabilization of the nitrosyl iron complexes by BSA were explained.