Table I.
Purification procedure of nodule trehalase from soybean
| Step | Total Protein | Trehalase Activity | Specific Trehalase Activity | Purification Factor |
|---|---|---|---|---|
| mg | nkat | nkat mg−1 protein | ||
| 1. Crude nodule extract (pH 3.7) | 5050 | 9682 | 1.917 | 1 |
| 2. Ion-exchange chromatography DEAE- Trisacryl (pH 6.5, 100 mm NaCl) | 575 | 7786 | 13.54 | 7 |
| 3. Concanavalin A-affinity chromatography | 47 | 4776 | 101.6 | 53 |
| 4. Gel filtration (Superose 12) | 3 | 1647 | 549.0 | 286 |
| 5. Hydroxylapatite-affinity chromatography | 0.55 | 661 | 1201 | 626 |
| 6. Ion-exchange chromatography (Hi-Trap Q, pH 6.5, 120 mm NaCl) | 0.018 | 90 | 5000 | 2608 |
The flow chart shows the optimized procedure for trehalase purification. As starting material, 888 g of soybean nodules was extracted as described by Müller et al. (1992). The individual steps of the purification procedure are given with the amount of total protein, total trehalase activity, specific trehalase activity, and the purification factor obtained at that step.