EC Number   |
Activating Compound |
Reference |
|---|
    2.4.2.8 | acetate |
slightly activating |
638391 |
| 2.4.2.8 | GMP |
0.05 mM, at least 2fold stimulation, hypoxanthine phosphoribosyltransferase activity |
727728 |
| 2.4.2.8 | IMP |
- |
736777 |
| 2.4.2.8 | IMP |
0.2 mM, at least 2fold stimulation, hypoxanthine phosphoribosyltransferase activity |
727728 |
| 2.4.2.8 | IMP |
activates the enzyme, activating effects on wild-type and mutant enzymes, overview. Upon activation of the mutants with IMP, the lag phase disappears, while an increase in the specific activity values appears. Although activation of wild-type and mutants by IMP increases their catalytic efficiency by about 100fold, it is found that the kcat/Km values for the mutants drop by 5.7 to 75fold when compared with the wild-type enzyme |
760104 |
| 2.4.2.8 | IMP |
activation with IMP results primarily in an increase in kcat, which is 3-5fold in the case of hypoxanthine and xanthine phosphoribosylation and more than 10fold in the case of guanine phosphoribosylation |
736785 |
| 2.4.2.8 | more |
activation by substrate and product IMP, reversibly destabilizes the enzyme |
661691 |
| 2.4.2.8 | more |
hypoxanthine phosphoribosyltransferase activity is unaffected by AMP |
727728 |
| 2.4.2.8 | more |
not activated by GMP or XMP |
736785 |
| 2.4.2.8 | phosphate |
the tetrameric enzyme activity increases in phosphate buffer, while the dimeric state, which occurs when excess magnesium ions are removed, is unable to be rapidly activated by phosphate and magnesium. Phosphate alone cannot activate the enzyme, magnesium ions are also required |
758862 |
