Figure 1.

Salts significantly tuned the reaction rate of the π-clamp mediated arylation on peptides. (a) π-Clamp-mediated site-specific conjugation on proteins. (b) Salts used in this study and their positions in the Hofmeister series. (c) Rate constants of the reactions between π-clamp peptide 1A and perfluoroaryl probe 2 with salts at different concentrations. The black dashed line indicates the rate constant with no additional salt. General reaction conditions for measuring rate constant: 200 mM phosphate, 20 mM TCEP, pH 8.0, 37 °C. (See Figures S1–S15 for detailed conditions of each reaction.) Error was obtained from linear fitting of the kinetics curves for measuring the reaction rate.