TABLE 2.
Substrate and coenzyme specificity of xylose reductase purified from C. parapsilosisa
| Substrate | Specific activity (U/mg of protein) | Km (mM) | kcat/Km (s−1 mM−1) |
|---|---|---|---|
| d-Xylose | 32.1 | 31.5 | 1.5 × 100 |
| d-Xyloseb | 2.62 | 244.3 | 1.9 × 10−2 |
| d-Erythrose | 6.54 | 151.7 | 8.9 × 10−2 |
| d-Ribose | 2.67 | 302.0 | 4.3 × 10−2 |
| d-Arabinose | 1.79 | 285.4 | 2.8 × 10−2 |
| d-Glucose | 0.34 | —e | — |
| d-Fructose | 0.28 | — | — |
| Glucuronate | NDd | — | — |
| Benzoquinone | ND | — | — |
| Xylitolc | 1.29 | 326.3 | 3.1 × 10−2 |
a
The purified enzyme was assayed in the standard assay condition for reduction with various substrates. Each value represents the mean of triplicate measurements and varied from the mean by not more than 10%.
b
NADPH was used instead of NADH.
c
Assay was performed in the standard assay condition for oxidation.
d
ND, not detectable.
e
—, not determined.