Tyrosine bioconjugation using stably preparable urazole radicals

Abstract

Our ex situ tyrosine bioconjugation method utilizes the oxidation of N-methylurazole by Bobbitt's salt or electrochemical activation to generate stable radicals for selective tyrosine labeling, thereby addressing the longstanding challenges in protein bioconjugation. Unlike traditional tyrosine conjugation techniques that rely on closed-shell chemistry with 1,2,4-triazoline-3,5-dione derivatives, this method introduces an alternative bond-forming mechanism that expands bioconjugation through a radical-based pathway that enhances tyrosine selectivity. The applicability of this method was demonstrated for various proteins and validated through proteome-wide analyses, highlighting its potential as a valuable tool for investigating protein function and interaction dynamics.