TABLE 1.
Buffer and reagent concentrations for enzyme assaysa
| Enzyme (EC no.) | Buffer | Cofactor | Reagents | Start reagent (concn) |
|---|---|---|---|---|
| XR (EC 1.1.1.21) | Triethanolamine (100 mM, pH 7.0) | NADPH (0.2 mM) | Xylose (350 mM) | |
| XDH (EC 1.1.1.9) | Glycine (100 mM, pH 9.0), MgCl2 (50 mM) | NAD+ (3.0 mM) | Xylitol (300 mM) | |
| XK (EC 2.7.1.17) | Tris-HCl (50 mM, pH 7.5), MgCl2 (2.0 mM) | NADH (0.2 mM) | Xylulose (8.5 mM), phosphoenol pyruvate (0.2 mM), pyruvate kinase (10 U), lactate dehydrogenase (10 U) | ATP (2.0 mM) |
| PGK (EC 2.7.2.3) | Tris-HCl (100 mM, pH 8.0), EDTA (0.9 mM), MgCl2 (2 mM) | NADH (0.2 mM) | ATP (1 mM), glyceraldehyde-3-phosphate dehydrogenase (1 U) | 3-Phosphoglycerate (20 mM) |
| ADH (EC 1.1.1.1) | Glycine (100 mM, pH 9.0) | NAD+ (5.0 mM) | Ethanol (1.7 M) |
a
All concentrations refer to the final assay mixture. The final assay volume was 1 ml.