TABLE 2.
Catalytic and structural properties of hydrazine dehydrogenase from K. stuttgartiensis and other hydrazine-oxidizing enzymes
Kinetic values are given for mammalian cytochrome c as electron acceptor. KSU-1, anammox strain KSU-1. NA, not applicable; NR, not reported.
| K. stuttgartiensis HDH | K. stuttgartiensis HOX | KSU-1 HZO/HDH | KSU-1 HOX | Brocadia anammoxidans HOX | Nitrosomonas europaea HAO | |
|---|---|---|---|---|---|---|
| Vmax N2H4 (μmol min−1 mg−1) | 11 ± 1.2 | 1.6 ± 0.0 | 6.2 | 0.54 | 1.1 | 14 |
| kcat N2H4 (s−1) | 36 | 4.9 | 13.4 | 1.1 | 3.4 | 47 |
| Km N2H4 (μm) | 10 ± 2.2 | 54 ± 3.3 | 5.5 | 25 | 18 | 4 |
| kcat/Km N2H4 (s−1 μm−1) | 3.5 | 0.1 | 2.4 | 0.042 | 0.19 | 12 |
| Vmax NH2OH (μmol min−1 mg−1) | NA | 4.8 ± 0.2 | NA | 9.6 | 21 | 28.5 |
| kcat NH2OH (s−1) | NA | 15 | NA | 19 | 64 | 95 |
| Km NH2OH (μm) | NA | 4.4 ± 0.9 | NA | 33 | 26 | 3.6 |
| kcat/Km NH2OH (s−1 μm−1) | NA | 3.4 | NA | 0.58 | 2.5 | 26 |
| Ki NH2OH (μm) | 7.9 ± 1.8 | NA | 2.4 | NA | NA | NA |
| Ki NO (μm) | 2.5 ± 0.9 | NA | NR | NR | NR | NA |
| Total size (kDa) | 201.5 (∼1,600) | 184 | 130 | 118 | 183 | 200 |
| Subunit size (kDa) | 67.2 | 61.3 | 62 | 53 | 58 | 66 |
| Subunit composition | α3 ((α3)8) | α3 | α2 | α2 | α3 | α3 |
| Catalytic heme optical maximum (nm) | 473 | 468 | 472 | 468 | 468 | 463 |
| Catalytic heme midpoint potential (mV) | −420 | −300 | NR | NR | NR | −260 |
| Reference | This paper | 12 | 8 | 17 | 18 | 19–21 |