TABLE 4.
Nucleotide specificity of ApbC
Inorganic phosphate release was detected after a 30-min incubation using the malachite green/molybdate/polyvinyl alcohol assay as described under “Experimental Procedures.” Assays were done in triplicate, and the error is listed as standard deviation. Unless indicated, assays contained 0–0.34 mg of purified ApbC, 6 mm MgCl2, 200 mm KCl, 5 mm nucleotide mono-, di-, or triphosphate, and 50 mm Tris, pH 8.0.
| Nucleotide (5 mm) | Pi release |
|---|---|
| nmol mg-1 | |
| ATP | 518 ± 18 |
| ATP - Mg2+ | NDa |
| ATP - K+ | 63 ± 27 |
| ATP + AMP | 429 ± 36 |
| ATP + ADP | ND |
| ADP | ND |
| AMP | ND |
| dATP | 261 ± 30 |
| CTP | 42 ± 21 |
| GTP | 75 ± 15 |
| TTP | ND |
| UTP | ND |
a
No phosphate release was detected.