Basa Prem N, Antala Sagar, Dempski Robert E, Burdette Shawn C
Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280 (USA).
Angew Chem Int Ed Engl. 2015 Oct 26;54(44):13027-31. doi: 10.1002/anie.201505778. Epub 2015 Sep 8.
Metal ion signaling in biology has been studied extensively with ortho-nitrobenzyl photocages; however, the low quantum yields and other optical properties are not ideal for these applications. We describe the synthesis and characterization of NTAdeCage, the first member in a new class of Zn(2+) photocages that utilizes a light-driven decarboxylation reaction in the metal ion release mechanism. NTAdeCage binds Zn(2+) with sub-pM affinity using a modified nitrilotriacetate chelator and exhibits an almost 6 order of magnitude decrease in metal binding affinity upon uncaging. In contrast to other metal ion photocages, NTAdeCage and the corresponding Zn(2+) complex undergo efficient photolysis with quantum yields approaching 30 %. The ability of NTAdeCage to mediate the uptake of (65) Zn(2+) by Xenopus laevis oocytes expressing hZIP4 demonstrates the viability of this photocaging strategy to execute biological assays.
生物学中的金属离子信号传导已通过邻硝基苄基光笼进行了广泛研究；然而，低量子产率和其他光学性质对于这些应用来说并不理想。我们描述了NTAdeCage的合成与表征，它是一类新型锌离子光笼中的首个成员，该光笼在金属离子释放机制中利用光驱动脱羧反应。NTAdeCage使用经过修饰的次氮基三乙酸螯合剂以亚皮摩尔亲和力结合锌离子，并且在脱笼后金属结合亲和力降低了近6个数量级。与其他金属离子光笼不同，NTAdeCage及其相应的锌离子络合物以接近30%的量子产率进行高效光解。NTAdeCage介导表达hZIP4的非洲爪蟾卵母细胞摄取（65）锌离子的能力证明了这种光笼策略用于进行生物学测定的可行性。
