Table 1.
Kinetic parameters of wild-type human CTRC and mutants N52S and E92T on the synthetic substrate Suc-Ala-Ala-Pro-Phe-p-nitroanilide, measured at 22 °C in 0.1 M Tris-HCl (pH 8.0), 1 mM CaCl2 and 0.05% Tween 20. CTRC was expressed in HEK 293T cells or in E. coli, as indicated. Note that the E92T mutant was created in the background of the non-glycosylated triple mutant N25S,N52S,N226S.
| KM (μM) | kcat (s−1) | kcat/KM (M−1 s−1) | |
|---|---|---|---|
| wild type | 13.8 ± 1.0 | 16.1 ± 0.2 | 1.2 × 106 |
| wild type (E. coli) | 13.8 ± 2.9 | 14.1 ± 0.6 | 1.0 × 106 |
| N52S | 13.6 ± 1.7 | 16.8 ± 0.4 | 1.2 × 106 |
| E92T | 19.3 ± 1.5 | 17.8 ± 0.3 | 0.9 × 106 |