Table 1. Kinetic constants of pyridoxal 5’-phosphate phosphatase (PDXP)-catalyzed pyridoxal 5’-phosphate (PLP) hydrolysis in the presence of 7,8-dihydroxyflavone (7,8-DHF).
Table 1—source data 1. Kinetic constants of pyridoxal 5’-phosphate phosphatase (PDXP)-catalyzed pyridoxal 5’-phosphate (PLP) hydrolysis in the presence of 7,8-dihydroxyflavone (7,8-DHF).
Data are OD values of malachite green assays, using PLP as a PDXP substrate, and derived kinetic constants.
elife-93094-table1-data1.xlsx (37.7KB, xlsx)
| 7,8-DHF [µM] | 0 | 1.0 | 1.5 | 2.0 | 3.0 | 5.0 | 10.0 |
|---|---|---|---|---|---|---|---|
| KM [µM] | 14.98 ±1.28 |
18.54 ±6.24 |
20.20 ±6.19 |
18.97 ±5.15 |
24.83 ±2.61 |
32.96 ±2.13 |
30.61 ±2.57 |
| vmax [µmol/min/mg] | 1.08 ±0.04 |
0.95 ±0.01 |
0.89 ±0.04 |
0.85 ±0.02 |
0.80 ±0.04 |
0.81 ±0.05 |
0.74 ±0.06 |
| kcat [s–1] | 0.57 ±0.02 |
0.5 ±0.01 |
0.47 ±0.02 |
0.45 ±0.01 |
0.42 ±0.02 |
0.43 ±0.03 |
0.39 ±0.03 |
| kcat/KM [s–1∙M–1] (×10–4) |
3.93 ±0.29 |
3.27 ±0.84 |
2.75 ±0.67 |
2.72 ±0.66 |
1.72 ±0.10 |
1.31 ±0.06 |
1.29 ±0.01 |
The data are mean values ± SEM of n=3 technically independent experiments, except for the solvent control samples (n=6). Curves were fitted and parameters KM (Michaelis-Menten constant); vmax (maximum enzyme velocity); kcat (turnover number) were derived using the Michaelis-Menten model in GraphPad Prism 9.5.1. The kcat values were calculated from the maximum enzyme velocities using a molecular mass of 31,828 Da for PDXP. DMSO concentrations were kept constant (0.1% DMSO under all conditions, including the solvent control samples). Source data are available for this table.