Fig. 2. Design elements. (a) Order of proteome reactivity for aryl sulphonate ester: Glu (E) ≫ Cys (C) ≈ Asp (D) > Tyr (Y) > His (H).35 (b) General structure of the chemoselective linchpin-equipped promiscuous electrophile, i.e., aryl sulphonate ester. (c) Control reagent (2a), and other bioconjugation reagents (2b–2f).
