Study of caffeine binding to human serum albumin using optical spectroscopic methods  

作　　者：WU Qiong LI ChaoHong HU YanJun LIU Yi 

机构地区：[1]College of Chemistry&Chemical Engineering,Hubei University,Wuhan 430062,China [2]State Key Laboratory of Virology&College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China [3]Key Laboratory for Oral Biomedical Engineering of MOE&School of Stomatology,Wuhan University,Wuhan 430072,China

出　　处：《Science China Chemistry》2009年第12期2205-2212,共8页中国科学（化学英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant Nos. 20873096, 20803019 & 20621502);Natural Science Foundation of Hubei Province (Grant No. 2005ABC002);Research Foundation of the Chinese Ministry of Education (Grant No. [2006]8-IRT0543);the 863 Program (Grant No. 2007AA06Z407)

摘　　要：The binding of caffeine to human serum albumin (HSA) under physiological conditions has been stud-ied by the methods of fluorescence,UV-vis absorbance and circular dichroism (CD) spectroscopy. The mechanism of quenching of HSA fluorescence by caffeine was shown to involve a dynamic quenching procedure. The number of binding sites n and apparent binding constant Kb were measured by the fluorescence quenching method and the thermodynamic parameters △H,△G,△S were calculated. The results indicate that the binding is mainly enthalpy-driven,with van der Waals interactions and hydrogen bonding playing major roles in the reaction. The distance r between donor (HSA) and acceptor (caffeine) was obtained according to the Frster theory of non-radiative energy transfer. Synchronous fluorescence,CD and three-dimensional fluorescence spectroscopy showed that the microenvironment and conformation of HSA were altered during the reaction.The binding of caffeine to human serum albumin (HSA) under physiological conditions has been studied by the methods of fluorescence, UV-vis absorbance and circular dichroism (CD) spectroscopy. The mechanism of quenching of HSA fluorescence by caffeine was shown to involve a dynamic quenching procedure. The number of binding sites n and apparent binding constant K b were measured by the fluorescence quenching method and the thermodynamic parameters ΔH, ΔG, ΔS were calculated. The results indicate that the binding is mainly enthalpy-driven, with van der Waals interactions and hydrogen bonding playing major roles in the reaction. The distance r between donor (HSA) and acceptor (caffeine) was obtained according to the F?rster theory of non-radiative energy transfer. Synchronous fluorescence, CD and three-dimensional fluorescence spectroscopy showed that the microenvironment and conformation of HSA were altered during the reaction.

关 键 词：CAFFEINE human serum ALBUMIN fluorescence QUENCHING circular DICHROISM (CD) SPECTROSCOPY UV-VIS spectroscopy. 

分 类 号：R96[医药卫生—药理学]