重金属镉离子人工合成抗原的荧光特性分析

Detection of Artifical Antigen for Cd(Ⅱ) by Fluorescence Spectrometry

以1-(4-异硫氰苄基)乙烯基二胺-N,N,N′,N′-四乙酸为双功能螯合剂,偶联Cd2+与血清蛋白质分子,合成了Cd2+人工抗原。利用荧光光谱分析了Cd2+人工合成抗原的荧光特性并得到合成反应的偶联比为11∶1～16∶1;通过荧光相图分析表明,Cd2+人工抗原合成过程中血清蛋白质的折叠状态符合"二态模型";偏振荧光光谱检测结果显示,Cd2+人工抗原合成中血清蛋白质色氨酸残基的微区构象发生一定变化,导致载体蛋白质构象改变。

Artificial antigen Cd-IEDTA-BSA （HSA） was successfully synthesized by the bifunctional chelating agent IEDTA （isothiocyanobenzylethyl enediamine tetraacetic acid ） coupling with cadmium and protein carrier. The fluorescence characteristics of antigen were determined by fluorescence spectrophotometry and the coupling ratio 11：1 -16：1 was obtained for the coupling reaction. The folding status of serum albumin during the synthesis process of artificial antigen Cd-IEDTA-BSA （HSA） was analyzed using ＂fluorescence phase diagram＂, and the result shows that it was conformed to the ＂all-or-none＂ pattern. The polarization fluorescence spectra show that the microenvironments of tryptophan residues in carrier protein have some changes to cause changes in protein conformation.