Spectroscopic Studies on the Interaction between Sulfadiazine and Human Serum Albumin

Abstract

The interaction of sulfadiazine (SDZ) and human serum albumin (HSA) in phosphate buffer solution had been investigated using multi-spectroscopic methods. The inner filter effect was corrected. The quenching mechanism was determined to be static quenching according to the fluorescence measurement. The thermodynamic parameters (enthalpy change (ΔH) and entropy change (ΔS)) were calculated to be-9.70 KJ·mol-1 and 46.07 J·mol-1·K-1, respectively, which indicated that hydrogen bonds and hydrophobic interactions play the major role on driven the interaction of SDZ with HSA. SDZ binds in the vicinity of site I in HSA, and the binding distance was 1.93 nm. In addition, the effects of HSA secondary structure were quantitatively calculated by CD spectra.