Table 2. Apparent Rate Constants (s–1) for the Oxidation of 1 mM Glc5 by LsAA9A under Various Conditionsa.
mono-oxygenase (Figure 6A; 1 mM reductant, 1 mM Glc5, O2) | oxidase (Figure 6B; 1 mM reductant, O2, no substrate) | O2 reduction, reductant only (Figure 2C; 1 mMreductant, O2, no LPMO) | peroxygenase (Figure 6C; 0.1 mM reductant, 1 mM Glc5, 300 μM H2O2, O2) | peroxygenase (Figure 6C; 1 mM reductant, 1 mM Glc5, 300 μM H2O2, O2) | |
---|---|---|---|---|---|
AscA | 0.014 ± 0.002 | 0.006 ± 0.000 (35%) | 0.0004 ± 0.0001 | 5.8 ± 2.3 | 23.4 ± 4.2 |
GA | 0.006 ± 0.001 | 0.002 ± 0.000 (100%) | 0.0040 ± 0.0009 | 0.1 ± 0.0 | 0.4 ± 0.1 |
cysteine | 0.029 ± 0.001 | 0.018 ± 0.000 (95%) | 0.0026 ± 0.0002 | 0.3 ± 0.1 | 0.2 ± 0.1 |
The values presented are estimates derived from the progress curves shown in Figure 6. The oxidase values are also expressed as a percentage of the oxidase value observed for NcAA9C (Table 1). Other quantitative comparisons between the two LPMOs are not straightforward due to the occurrence of substrate inhibition in the reactions with LsAA9A.