TABLE 3.
Biochemical characteristics of recombinant purified C. albicans Hpd1p
All values were determined at 22 °C in CHES buffer, pH 9.5.
| Substrate | Aspec (exp)a | Aspec (theo)b | Km | Km (NAD) | kcatc | Keff |
|---|---|---|---|---|---|---|
| units/mg | units/mg | mm | mm | s−1 | m−1 s−1 | |
| 3-Hydroxy-propionate | 40.7 (@36 mm) | 47.40 | 5.37 | 0.22 | 30.97 | 5.77 × 103 |
| (S)-β-Hydroxyisobutyrate | 3.62 (@10 mm) | 3.79 | 0.13 | 0.02 | 2.48 | 1.91 × 104 |
| (R)-β-Hydroxyisobutyrate | 1.85 (@10 mm) | 2.00 | 0.58 | NDd | 1.31 | 2.26 × 103 |
| l-Serine | 5.16 (@30 mm) | 14.40 | 46.7 | NDd | 9.41 | 2.02 × 102 |
a Maximum-specific activities as determined experimentally at given substrate concentrations are shown in parentheses.
b Theoretic maximum-specific activities as deduced from Lineweaver-Burk diagrams.
c Turnover numbers were calculated assuming one active site per subunit, a molecular mass of 39.2 kDa for the recombinant enzyme, and using the theoretical maximum activity value.
d ND = not determined.