Table 3.
Catalytic properties of recombinant 3-hydroxypropionyl-CoA synthetase and recombinant 4-hydroxybutyryl-CoA synthetase from N. maritimus
| Substrate | 3-Hydroxypropionyl-CoA synthetase |
4-Hydroxybutyryl-CoA synthetase |
||||
| Vmax, µmol⋅min −1⋅mg −1 protein | Km, mM | kcat/Km | Vmax, µmol⋅min −1⋅mg −1 protein | Km, mM | kcat/Km | |
| 3-Hydroxypropionate | 0.59 ± 0.03 | 1.2 ± 0.2 | 0.64 | – | – | – |
| 4-Hydroxybutyrate | 0.48 ± 0.04 | 5.6 ± 1.0 | 0.11 | 1.4 ± 0.01 | 0.37 ± 0.06 | 4.88 |
| Acetate | – | – | – | 0.22 ± 0.01 | 200 ± 5 | 0.001 |
| Propionate | 0.50 ± 0.10 | 17.0 ± 6.0 | 0.04 | 0.10 ± 0.01 | 88 ± 7 | 0.002 |
| Butyrate | 0.54 ± 0.01 | 12.4 ± 0.3 | 0.06 | 0.61 ± 0.05 | 5 ± 1 | 0.16 |
| ATP | 0.59 ± 0.03 | 0.6 ± 0.1 | 1.28 | 1.7 ± 0.2 | 0.22 ± 0.07 | 9.96 |
| CoA | 0.60 ± 0.10 | 0.16 ± 0.09 | 4.85 | 1.4 ± 0.1 | 0.16 ± 0.05 | 11.28 |
Neither synthetase was active with the following substrates: crotonate, acetoacetate, (S)-3-hydroxybutyrate, (R)-3-hydroxybutyrate, succinate, (RS)-malate, itaconate, (S)-citramalate. –, no activity detected.