Spectroscopic and docking molecular study of new anticancer Pt complex binding with human serum albumin.

After synthesizing and identifying the nature of the new complex based on platinum metal, [Pt(NH3)2(butylgly)]NO3, the interaction of this complex with human serum albumin (HSA) was performed by spectroscopy and molecular docking methods at two temperatures of 27 and 37 °C and under physiological conditions of the body. The toxicity test of this complex was performed on the MCF-7 cell line (IC50 = 300 µM). Enthalpy, entropy, Gibbs free energy, binding constant, number of complex binding sites on the HSA, Scatchard diagrams, Hill coefficient, and Hill constant were calculated and then plotted via UV/Vis. According to the Gibbs free energy obtained at two temperatures of 27 and 37 °C (-20.6, -21.2 kJ mol-1), the interaction was done spontaneously. Moreover, the melting temperature of human serum albumin with this complex; and the kinetics of this interaction (the second-order) were calculated. Using fluorescence at three temperatures of 25, 27, and 37 °C, the binding constant (2.9 × 104, 1.0 × 104, and 5.7 × 103 M-1), the quenching constant, average aggregation number of HSA, and the number of binding sites of the complex on the protein were obtained. As well, the static quenching mechanism was also observed. Molecular docking results showed that the site of binding of this complex to the HSA, is the site II subdomain IIIA, and the hydrogen and hydrophobic bonds are superior.

Kinetic and Thermodynamic Investigation of Human Serum Albumin Interaction with Anticancer Glycine Derivative of Platinum Complex by Using Spectroscopic Methods and Molecular Docking.

In this paper, a new anticancer Pt (II) complex, cis-[Pt (NH3)2(tertpentylgly)]NO3, was synthesized with glycine-derivative ligand and characterized. Cytotoxicity of this water-soluble Pt complex was studied against human cancer breast cell line of MCF-7. The interaction of human serum albumin (HSA) with Pt complex was studied by using UV-Vis, fluorescence spectroscopy methods, and molecular docking at 27 and 37 °C in the physiological situation (I = 10 mM, pH = 7.4). The negative [Formula: see text] and positive [Formula: see text] indicated that electrostatic force may be a major mode in the binding between Pt complex and HSA. Binding constant values were obtained through UV-Vis and fluorescence spectroscopy that reveal strong interaction. The negative Gibbs free energy that was obtained by using the UV-Vis method offers spontaneous interaction. Fluorescence quenching the intensity of HSA by adding Pt complex confirms the static mode of interaction is effective for this binding process. Hill coefficients, nH, Hill constant, kH, complex aggregation number around HSA, , number of binding sites, g, HSA melting temperature, Tm, and Stern-Volmer constant, kSV, were also obtained. The kinetics of the interaction was studied, which showed a second-order kinetic. The results of molecular docking demonstrate the position of binding of Pt complex on HSA is the site I in the subdomain IIA.