TABLE 1.
Localization and purification of a maltose-binding protein from T. ethanolicus
| Fraction | Amt of protein (mg) | Amt of maltose bound (nmol)a | Sp act (nmol/mg) | Purification (fold) | Yield (%) |
|---|---|---|---|---|---|
| Localization | |||||
| Crude extract | 15.0 | 2.2 | 0.15 | 1 | 100 |
| Cytosol | 11.9 | 0.8 | 0.07 | ||
| Membrane | 2.2 | 1.8 | 0.82 | 5.5 | 82 |
| Extracted membraneb | 1.4 | 1.3 | 0.93 | 6.2 | 59 |
| Purification | |||||
| Crude extract | 172 | 24.1 | 0.14 | 1 | 100 |
| Affinity fraction | 0.01 | 0.1 | 10.0 | 71.4 | 0.42 |
a
Binding activity was determined by a filter-binding assay. Fractions were prewarmed for 30 s at 70°C before [14C]maltose (final concentration, 0.69 μM; 360 mCi/mmol) was added.
b
Membranes were extracted with 1% octyl-β-glucoside for 75 min at 4°C.