Developing a dual-channel fluorescent probe for discriminating monothiol- or vicinal dithiol-contain

• 作 者: Wei Gao Miao Zhang Jinghui Wang Yibing Zhao Chuanliu Wu
• 机 构: College of Chemistry and Chemical Engineering,The MOE Key Laboratory of Spectrochemical Analysis and
• 出 处: 2016年分析化学前沿国际研讨会及中美分析化学研讨会
• 发表日期: 2016年3期
• 关键词: vicinal dithiol-containing proteins probe dual-channel

　　Many proteins contain cysteine residues,which play an important role in keeping the redox state,precise folding and stabilization of proteins.Consequently,evaluating the distribution of cysteine-containing proteins using visualization techniques is one of the key issues in field of biochemistry and molecular biology.In this study,a dual-channel fluorescent off-on probe with two thiol-reactive sites(CyDS)was designed and synthesized(Figure 1),which can discriminate monothiol-and vicinal dithiol-containing proteins.Serum albumin(BSA)and its reduced form(rBSA)were selected as the model protein for the exploration.Only site-1 of CyDS can react with the free thiol,and in this case the conjugate structure preserved; thus the fluorescence intensity at 575 nm was enhanced as a result of the changes of the microenvironment of the conjugated CyDS.Eight vicinal Cys residues will be generated when BSA was reduced with tris(2-carboxyethyl)phosphine(TCEP).Thus rBSA can react with both the site1 and site2 of CyDS,resulting in disruption of the conjugate structure; as a consequence the fluorescence intensity at 475 nm was enhanced.By comparing the fluorescence intensity at the two different channels(475 and 575 nm),the distribution of thiol-containing proteins might be visualized through fluorescent imaging.