Interaction of human serum albumin with bendroflumethiazide studied by fluorescence spectroscopy.
The interactions between bendroflumethiazide (BFTZ) and human serum albumin (HSA) have been studied by fluorescence spectroscopy. Binding constants for drug attachment to the various binding sites of HSA have been measured at different temperatures in physiological buffer solution. The effect of metal ions on BFTZ interaction with HSA was also investigated. The thermodynamic parameters, DeltaH and DeltaS, have been calculated to be 49.28kJmol(-1)>0, and 258.83Jmol(-1)K(-1)>0, respectively. The distance between HSA and BFTZ, r, was determined to be 1.47nm based on Förster's non-radiative energy transfer theory. The experimental results reveal that BFTZ has a strong ability to quench the intrinsic fluorescence of HSA through a static quenching mechanism. Furthermore, the binding constants between BFTZ and HSA are remarkably independent of temperature, and decrease in the presence of various ions, usually by about 30-55%. Hydrophobic interaction occurs between BFTZ and the sub-domain II A of HSA.
Pang
Yue Hong
YH
Institute of Advanced Chemistry, College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.
Yang
Li Li
LL
Shuang
Shao Min
SM
Dong
Chuan
C
Thompson
Michael
M
D001539:Bendroflumethiazide / Q000737:chemistry* / Q000378:metabolism; D004735:Energy Transfer; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism; D049993:Sodium Chloride Symporter Inhibitors / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013816:Thermodynamics
D012709:Serum Albumin; D049993:Sodium Chloride Symporter Inhibitors; D001539:Bendroflumethiazide