Synthetic Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands.
Org Biomol Chem. 2013 May 7;11(17):2772-9. doi: 10.1039/c3ob00043e. Epub 2013 Mar 13.
Strain-promoted alkyne-nitrone cycloadditon (SPANC) was optimized as a versatile strategy for dual functionalization of peptides and proteins. The usefulness of the dual labeling protocol is first exemplified by the simultaneous introduction of a chloroquine and a stearyl moiety, two endosomal escape-improving functional groups, into the cell-penetrating peptide hLF (human lactoferrin). Additionally, we demonstrate that dual labeling of proteins is feasible by combining metal-free and copper-catalyzed click chemistry. First, SPANC is applied to enhanced green fluorescent protein to introduce both biotin and a terminal alkyne. The terminal acetylene then serves as a convenient anchor point for the CuAAC reaction with azido-containing fluorescein, thereby demonstrating the potential of combined SPANC and CuAAC for the straightforward, dual functionalization of proteins.
应变促进炔基-硝酮环加成（SPANC）被优化为一种用于肽和蛋白质双重功能化的通用策略。双标记方案的有用性首先通过同时引入氯喹和硬脂基两个内体逃逸增强功能基团到穿透肽 hLF（人乳铁蛋白）中得到例证。此外，我们通过结合无金属和铜催化点击化学证明了蛋白质双标记是可行的。首先，SPANC 被应用于增强型绿色荧光蛋白，以引入生物素和末端炔基。然后，末端乙炔可作为与含叠氮化物的荧光素的 CuAAC 反应的方便锚定点，从而证明了 SPANC 和 CuAAC 用于蛋白质的直接双重功能化的潜力。
