3种天然色素与人唾液富组蛋白5亲和力的比较

目的：本研究旨在用3种天然酚式色素——茶黄素、姜黄素和矢车菊素猝灭人唾液富组蛋白5的内源性荧光，从而在分子机制水平研究不同色素与H5之间的亲和力差异。方法：应用荧光分光光度计检测不同色素导致H5内源性的蛋白质荧光猝灭的效果。通过获得的荧光光谱，判断3种色素对H5的荧光猝灭类型并计算相应的荧光猝灭常数。数据采用单因素方差分析及SNK—q检验统计，检验水平α=0．05。结果：TF和Cur对H5的荧光猝灭类型以静态猝灭为主，同时伴随动态猝灭，而Cy对H5猝灭类型为静态猝灭。猝灭能力表现为Cy〉TF和Cur（P〈0．05）。结论：只有Cy会导致H5蛋白质分子构象发生改变。在溶液环境中，色素与H5之间的亲和力为Cy〉TF和Cur（P〈0．05）。

Comparison of the Affinity of Pigments with Human Salivary Histatin--rich 5.

Objective： To study the differences of binding affinity of three kinds of natural phenolic pigments （theaflavin,TF; curcumin,Cur and cyaniding,Cy） to human salivary histatin--rich 5 （HS） by fluorescence quench- ing of protein intrinsic fluorescence on molecular level. Methods： We compared the effects of different kinds of pigments quenching of H5 intrinsic fluorescence by the fluorescence spectrophotometer. The types of fluorescence quenching were confirmed and the quenching constants were calculated from the fluorescence spectra obtained. The data were analyzed by AVNOA and SNK--q test. The level of significance was defined as α= 0.05. Results： Both the fluorescence quenching of TF/H5 and Cur/H5 were dominant static quenching reaction, accompanied with the dynamic quenching, and the type of Cy/H5 was a static quenching. The effects of fluorescence quenching were Cy TF and Cur （P〈0.05）. Conclusion： Under the solution conditions, Cy could change molecular conformation of HS. The affinities of pigments binding with H5 were Cy 〉 TF and Cur （P〈0.05）.