TABLE 1.
Kinetic parameters of ANME2c-FsrII-6Da
| Substrate concentrations | Km (μM) for the varied substrate | Kcat (min−1) | kcat/Km (μM−1 min−1) (with respect to the varied substrate) | Reaction (electron donor) |
|---|---|---|---|---|
| NO2−, 500 μM; F420H2, varied (1–80 μM) | 14 ± 2 (F420H2) | 19 ± 1 | 2 ± 0.3 (F420H2) | NO2− reduction (F420H2) |
| F420H2, 40 μM; NO2−, varied (2–100 μM) | 5 ± 1 (NO2−) | 18 ± 1 | 4 ± 1 (NO2−) | NO2− reduction (F420H2) |
| F420H2, 40 μM; NH2OH, varied (2–500 μM) | 11 ± 1 (NH2OH) | 130 ± 3 | 12 ± 2 (NH2OH) | NH2OH reduction (F420H2) |
| HSO3−, 1,000 μM; MV·+, varied (29–408 μM) | 137 ± 26 (MV·+) | 64 ± 5 | 0.5 ± 0.1 (MV·+) | HSO3− reduction (MV·+)b |
| MV·+, 408 μM; HSO3−, varied (10–500 μM) | 129 ± 20 (HSO3−) | 64 ± 4 | 0.5 ± 0.1 (HSO3−) | HSO3− reduction (MV·+)b |
a
Km, Michaelis-Menten constant; kcat, turnover number expressed in terms of number of electrons transferred per enzyme subunit per min; kcat/Km, catalytic efficiency with respect to the varied substrate.
b
Nitrite reduction activity could not be assayed with MV·+ as the electron donor because NO2− oxidizes MV·+ chemically.