Interaction Between Baicalein and Amyloid-β Fibrils Studied by Fluorescence Spectroscopy  

作　　者：SONG Sheng-mei WANG Yong-xiang XIONG Li-min QU Ling-bo XU Mao-tian 

机构地区：[1]Department of Chemistry, Zhengzhou University, Zhengzhou 450052, P. R. China [2]Key Laboratory Cultivation Base of Nanobiological Analytical Chemistry ofHenan Province, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R.China

出　　处：《Chemical Research in Chinese Universities》2013年第1期20-25,共6页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China（Nos.21175091, 21205076） and the Key Scientific and Technological Project of Henan Province, China（No. 122102310478）.

摘　　要：The interaction between baicalein and amyloid-β（Aβ） polypeptide was investigated by fluorescence and UV-Vis absorbance spectroscopy. The absence of the characteristic peak of tyrosinate（Tyr） in the absorption spectra of Afl-baicalein complexes provided evidence that the sole Tyr residue in Aβis not bound to baicalein, but remains close to it. The intrinsic fluorescence of Tyr residues in Aβ1-42 aggregates was quenched strongly by the excited-state ionization of baicalein. In this complex the hydroxyl group was not ionized, but to ionize immediately upon excitation. Absorbance, fluorescence and synchronous spectroscopies show that the formation of Schiff base between the quinone of baicalein and the lysine（Lys） side chains ofAβ1-42 is another major reason in the depolymerization of Aβ1-42 aggregates by baicalein. It is desirable that our research would offer some valuable reference for the application of flavonoid derivants in Alzheimer＇s disease（AD） treatment.The interaction between baicalein and amyloid-β（Aβ） polypeptide was investigated by fluorescence and UV-Vis absorbance spectroscopy. The absence of the characteristic peak of tyrosinate（Tyr） in the absorption spectra of Afl-baicalein complexes provided evidence that the sole Tyr residue in Aβis not bound to baicalein, but remains close to it. The intrinsic fluorescence of Tyr residues in Aβ1-42 aggregates was quenched strongly by the excited-state ionization of baicalein. In this complex the hydroxyl group was not ionized, but to ionize immediately upon excitation. Absorbance, fluorescence and synchronous spectroscopies show that the formation of Schiff base between the quinone of baicalein and the lysine（Lys） side chains ofAβ1-42 is another major reason in the depolymerization of Aβ1-42 aggregates by baicalein. It is desirable that our research would offer some valuable reference for the application of flavonoid derivants in Alzheimer＇s disease（AD） treatment.

关 键 词：Amyloid-β peptide BAICALEIN DEPOLYMERIZATION Molecular mechanism Fluorescence spectroscopy 

分 类 号：O614.33[理学—无机化学] O614.121[理学—化学]