On Demand Attachment and Detachment of -2-Br-DMNPA Tailoring to Facilitate Chemical Protein Synthesis.

Herein, we developed a bifunctional reagent -2-Br-DMNPA for the late-stage protection of peptide cysteine. Through the identification of its -Bu ester as a more competent form under ligation conditions, facile N-terminal and side-chain caging for the model peptide and protein were accomplished. Building upon this, a one-pot ligation and photolysis strategy was applied in the synthesis of the mini-protein chlorotoxin. More importantly, we extended the utility of as a bifunctional linker for traceless solid-phase chemical ligation.