A thiol-selective and acid-stable protein modification strategy using an electron-deficient yne reagent.

A protein modification strategy was developed based on a thiol-yne click reaction using an electron-deficient yne reagent. This approach demonstrated exceptional selectivity towards thiols and exhibited rapid kinetics, resulting in conjugates with superior acid stability. The conjugation of IgG with an indole-derived fluorophore was achieved for the imaging of PD-L1 in cancer cells.