Study of the interaction between icariin and human serum albumin by fluorescence spectroscopy

✍ Scribed by Guowen Zhang; Qingmin Que; Junhui Pan; Jinbao Guo

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 501 KB
• Volume: 881
• Category: Article
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2007.09.002

✦ Synopsis

The interaction between icariin and human serum albumin (HSA) in physiological buffer (pH 7.4) was investigated by fluorescence and UV-Vis absorption spectroscopy. Results obtained from analysis of fluorescence spectrum and fluorescence intensity indicated that icariin has a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. The thermodynamic parameters, DH h and DS h , were calculated to be 12.29 kJ mol À1 > 0, and 47.08 J mol À1 K À1 > 0, respectively, which suggested that hydrophobic force plays a major role in the reaction of icariin with HSA. The binding constants of icariin with HSA were determined at different temperatures by fluorescence quenching method. The distance r between donor (HSA) and acceptor (icariin) was calculated to be 4.18 nm based on Fo ¨rster's non-radiative energy transfer theory. The results of synchronous fluorescence spectra and three-dimensional fluorescence spectra showed that binding of icariin to HSA can induce conformational changes in HSA.