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.