Spectroscopic study and molecular simulation: Bovine serum albumin binding with anticancer Pt complex of amyl dithiocarbamate ligand

Abstract

Until now, many methods have been proposed to treat cancer, such as radiation therapy and drug therapy, but none of them have caused a complete cure for cancer. Heavy metal complexes such as cisplatin are among the compounds used as drugs in chemotherapy against cancer cells. These compounds cause cell death and have anti-cancer properties, but they have side effects. The biochemical mechanism of cisplatin is related to its interaction with DNA through covalent binding. To reduce the toxicity of metallodrugs, new complexes can be designed containing S, S- bidentate ligands such as diethyldithiocarbamate. Moreover, anti-cancer compounds probably interact with proteins, such as HSA, before passing the cancerous cell membrane and DNA as a target. So, the function of proteins and their stabilities are expected to change. In this research, the mode of binding of [Pt (bpy) (amyl.dtc)]NO3 complex with BSA was evaluated by various thermodynamic methods. Negative binding enthalpy and entropy changes amounts show that the connection between the Platinum compound and BSA occurs via the van Der Waals type of hydrogen bond. The negative Gibbs free energy change was obtained through isothermal titration, which showed interaction proceeds spontaneously. Moreover, the emission titration data showed that protein fluorescence quenching by platinum agent titration is static. Binding, quenching constants, and binding site number were obtained by the Stern-Volmer equation, and only one binding site was determined for this interaction. A Scatchard plot with a positive slope shows the Pt agent-BSA formation is proceeding positively cooperative. The kinetic study displayed that the absorption monitoring followed the second-order model. Finally, molecular docking simulation showed that the position of the Pt agent on protein is placed I under region II.