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 sp...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.展开更多
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）.
文摘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.
