Table 1.
HPR2 Is an NADPH-Dependent Hydroxypyruvate Reductase but Shows Relaxed Substrate and Cofactor Specificity and Is Strongly Inhibited by Oxalate
| Hydroxypyruvate Reductase | Without Oxalate Mean ± sd | With Oxalate Mean ± sd | % |
|---|---|---|---|
| HPR2 | |||
| Hydroxypyruvate:NADH | 1.40 ± 0.12 | 0.300 ± 0.080 | 21 |
| Hydroxypyruvate:NADPH | 5.50 ± 0.43 | 0.700 ± 0.090 | 13 |
| Glyoxylate:NADH | 0.36 ± 0.02 | 0.010 ± 0.001 | 3 |
| Glyoxylate:NADPH | 4.60 ± 0.36 | 0.100 ± 0.026 | 2 |
| HPR1 | |||
| Hydroxypyruvate:NADH | 222.00 ± 15.70 | 147.000 ± 22.000 | 66 |
| Hydroxypyruvate:NADPH | 12.00 ± 1.40 | 11.600 ± 1.100 | 97 |
| Glyoxylate:NADH | 6.40 ± 0.60 | 5.800 ± 0.4000 | 90 |
| Glyoxylate:NADPH | 0.26 ± 0.03 | 0.200 ± 0.020 | 77 |
Mean activities ± sd from three measurements with tag-purified recombinant HPR2 and HPR1 (μmol·min−1·mg−1 protein) or percentage values after inhibition are shown.