Spectroscopic studies on the binding of sibutramine hydrochloride and bovine serum albumin
Chen, C-yun.; Long, Q.; Lu, Y.; Xiang, B-ren.
Yao Xue Xue Bao 41(2): 175-178
2006
ISSN/ISBN: 0513-4870 PMID: 16671551 Document Number: 599807
Aim To study the binding of sibutramine hydrochloride (SH) and bovine serum albumin (BSA) in physiological condition by spectroscopic method. Methods The (quenching mechanism of the fluorescence of bovine serum albumin by sibutramine hydrochloride was studied with the fluorescence and the absorption spectroscopy. The binding constants K and the number of binding sites were determined at different temperatures according to Scatchard equation and the main binding force was discussed by thermodynamic equations. The effect of the drug on bovine serum albumin conformation was also studied by using synchronous fluorescence spectroscopy. Results The quenching mechanism of sibutramine hydrochloride to bovine serum albumin was static quenching. The binding constants K at 8 degrees C, 25 degrees C 37 degrees C were 1.21 x 10(5), 8.31 x 10(4), 6.97 x 10(4) L . mol(-1) with one binding site, respectively. The thermodynamic parameters of the reaction were Delta H = -9.70 kJ . mol(-1), Delta S = 56.41 J . mol(-1) . K-1. Conclusion The binding force is electrostatic interaction. Sibutramine hydrochloride can he deposited and transported by serum protein in. vivo. Sibutramine hydrochloride has nearly no effect on the serum protein conformation.