Table 2. Reactivity and Selectivity of Aryl Nitriles^a.

^aA mixture of 5 μM Ub-peptide fusion protein, 500 μM aryl nitrile, and 1 mM TCEP was incubated in NH₄HCO₃ buffer/acetonitrile (1:1), pH 8.5, at 37 °C for 1 h.

^bConversion was determined by LC-MS as described previously. Data shown are averages of two independent measurements ± standard deviation. See Table S11 and Figure S4 for details. ND, not determined.