The binding characteristics of the interaction between 3-(2-cyanoethyl) cytosine and human serum albumin.

The binding characteristics of the interaction between 3-(2-cyanoethyl) cytosine (CECT) and human serum albumin (HSA) were investigated using fluorescence, UV absorption spectroscopic and molecular modeling techniques under simulative physiological conditions. The intrinsic fluorescence intensity of HSA was decreased with the addition of CECT. The fluorescence data handled by Stern-Volmer equation proved that the quenching mechanism of the interaction between CECT and HSA was a static quenching procedure. The binding constants evaluated utilizing the Lineweaver-Burk equation at 17, 27 and 37 °C, were 2.340 × 10(4), 2.093 × 10(4) and 1.899 × 10(4) L mol(-1), respectively. The thermodynamic parameters were calculated according to van't Hoff equations. Negative enthalpy (ΔH) and positive entropy (ΔS) values indicated that both hydrogen bond and hydrophobic force played a major role in the binding process of CECT to HSA, which was consistent with the results of the molecular modeling study. In addition, the effect of other ions on the binding constant of CECT-HSA was examined.