The substrate has the following kinetic constants for βI tryptase: kcat of 18.34 ± 0.33 s-1, km of 23.4 ± 2.3 μm, kcat/Km of (0.78 ± 0.07) X 106 s−1 m−1. The substrate has the following kienetic constants for βII tryptase: kcat of 18.67 ±0.30 s-1, km of 14.7 ± 1.4 μm, kcat/Km of (1.27 ± 0.12) X 106 s−1 m−1.