Table 2.
Kinetic parameters of thiosulfate sulfurtransferase activity of STR18 and its C47S and C89S variants
| Protein | KM (μM) | kcat (s−1) | kcat/KM (M−1 s−1) |
|---|---|---|---|
| STR18 | 527 ± 8 | 5.1 ± 0.1 | 9.7 ± 0.2 × 103 |
| STR18 C47S | 333 ± 15 | 2.5 ± 0.1 | 7.5 ± 0.2 × 103 |
| STR18 C89S | ND | ND | ND |
The TST activity of STR18, C47S, and C89S variants was monitored in the presence of varying concentrations of thiosulfate as described in the “Experimental procedures” section. The apparent KM and turnover values (kcat) were calculated by nonlinear regression using the Michaelis–Menten equation. The data are represented as mean ± SD of three independent experiments.
Abbreviation: ND, not detected.