Spectroscopic characterization on the interaction between synthesized platinum(II) based drug and human serum albumin

Document Type : Regular Paper

Authors

1 Department of Chemistry, University of Zabol

2 Department of Chemistry, University of Sistan & Baluchestan, Zahedan

Abstract

The interaction of an organoplatinum(II) complex [Pt(pr-dtc)(bpy)]NO3 (where pr-dtc = propyldithiocarbamate and bpy = 2,2ˊ-bipyridine), as anticancer agent with human serum albumin (HSA) in aqueous solution at pH 7.4 has been studied by fluorescence, UV−Vis absorption spectra and CD spectroscopy. The quenching constants and binding parameters were determined by fluorescence quenching method. The obtained results revealed that there is a strong binding interaction between Pt(II) complex and HSA. The calculated thermodynamic parameters (ΔG, ΔH, and ΔS) confirmed that the binding reaction is mainly entropy-driven, and hydrophobic forces played a major role in the reaction. The binding distance (r) between the Pt(II) complex (acceptor) and HSA (donor) was obtained based on Försters theory of non-radiation energy transfer. Finally, the results of CD and UV–Vis spectroscopy showed that the binding of this complex to HSA induced conformational changes in protein. We hope that such spectroscopic studies between this complex and HSA give us key insights into the transportation, distribution and toxicity of newly design antitumor Pt(II) complexes in human blood.

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