Near-Infrared Fluorescence Probes for Enzymes Based on Binding Affinity Modulation of Squarylium Dye Scaffold

详细信息    查看全文

• 作者：Daihi Oushiki ; Hirotatsu Kojima ; Yuki Takahashi ; Toru Komatsu ; Takuya Terai ; Kenjiro Hanaoka ; Makiya Nishikawa ; Yoshinobu Takakura ; Tetsuo Nagano
• 刊名：Analytical Chemistry
• 出版年：2012
• 出版时间：May 15, 2012
• 年：2012
• 卷：84
• 期：10
• 页码：4404-4410
• 全文大小：361K
• 年卷期：v.84,no.10(May 15, 2012)
• ISSN：1520-6882

文摘

We present a novel design strategy for near-infrared (NIR) fluorescence probes utilizing dye鈥損rotein interaction as a trigger for fluorescence enhancement. The design principle involves modification of a polymethine dye with cleavable functional groups that reduce the dye鈥檚 protein-binding affinity. When these functional groups are removed by specific interaction with the target enzymes, the dye鈥檚 protein affinity is restored, protein binding occurs, and the dye鈥檚 fluorescence is strongly enhanced. To validate this strategy, we first designed and synthesized an alkaline phosphatase (ALP) sensor by introducing phosphate into the squarylium dye scaffold; this sensor was able to detect ALP-labeled secondary antibodies in Western blotting analysis. Second, we synthesized a probe for 尾-galactosidase (widely used as a reporter of gene expression) by means of 尾-galactosyl substitution of the squarylium scaffold; this sensor was able to visualize 尾-galactosidase activity both in vitro and in vivo. Our strategy should be applicable to obtain NIR fluorescence probes for a wide range of target enzymes.