Study on interaction between valsartan and human serum albumin by fluorescence spectrometry

The mechanism of interaction between valsartan and human serum albumin(HSA)was studied by using fluorescence spectrometry.The experimental results showed that the fluorescence quenching behavior of valsartan and HSA was a kind of static quenching.The binding constants(K30 ℃=761.8 and K37 ℃=374.8)and the number of binding sites(n30 ℃=0.53 and n37 ℃=0.48)of valsartan to HSA at different temperatures were determined,and the binding constants(KCa=3 899.5,KCu=1 081.4,KFe=1 595.1 and KZn=3 833.6)in the presence of metal ions were also obtained.Judging from thermodynamic parameters(ΔH=-24.9 kJ/mol,ΔS30 ℃=38.2 J·mol-1·K-1,and ΔS37 ℃=34.5 J·mol-1·K-1)it could be determined that their main binding force was the static electric power.The binding distance(r=2.07 nm)was measured according to the theory of Frster non-radiation energy transfer.The effect of valsartan on the conformation of HSA was analyzed by synchronous fluorescence spectrometry.