A Comparative Study On The Interaction Of New Designed Aliphatic Pd(II) Complexes With Human Serum Albumin

Abstract

Human serum albumin (HSA) is the most abundant protein in the systemic circulation, with comprising 60% in plasma. This protein can play a dominant role on the drug disposition and the efficiency. The pharmacokinetics and pharmacodynamics of any drug depend, largely, on the interaction with HSA. Hence, in present study, the interaction between new designed Pd(II)-complexes, 2,2′-bipyridin ethylglycinato Pd(II) nitrate, 2,2′-bipyridin butylglycinato Pd(II) nitrate and 2,2′-bipyridin octylglycinato Pd(II) nitrate, anti-tumor components, with human serum albumin as a carrier protein, were studied at different temperatures of 27 and 37° C by fluorescence spectroscopy, circular dichroism (CD) spectrophotometry and differential scanning calorimetry (DSC) techniques. Results showed Pd(II)-complexes have strong ability to quench the intrinsic fluorescence of HSA through static quenching procedure . The binding parameters were evaluated by fluorescence quenching method. From enthalpy and entropy of binding, it can be concluded that hydrophobic interactions may play an important role in the binding of Pd(II)-complexes to HSA. Far-UV-CD results represented that Pd(II)-complexes induced decreasing in content of α helical structure of protein.From above results, it can be concluded that the blood carrier protein of HSA could bind and transfer of these new anti-cancer drugs, but the stability of the protein decreased upon the interaction with this complexes.Keywords: Pd(II) complex, DSC, HAS, Quenching, Thermodynamic parameters.