Human ribonucleotide reductase. Activation and inhibition by analogs of ATP.
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Harrington JA, Spector T
Human ribonucleotide reductase. Activation and inhibition by analogs of ATP.
Biochem Pharmacol. 1991 Jul 25;42(4):759-63.
- PubMed ID
- 1867633 [ View in PubMed]
- Abstract
Sixteen ATP analogs were studied as activators of CDP reduction catalyzed by human ribonucleotide reductase. Activation constants were determined. Three analogs, 3-deazaATP, 5'-adenylimidodiphosphate, and 3'-dATP, activated approximately as efficiently as ATP. Four analogs were partial activators. These seven activators were also accessory activators of GDP reduction. Furthermore, two other analogs, adenosine-5'-O-(1-thiotriphosphate) and 8-bromoATP, selectively stimulated GDP reduction. Ten analogs, at equal molar concentrations with ATP, inhibited ATP-dependent activation of CDP reduction and/or accessory activation of GDP reduction by greater than 45%. No analog inhibited as potently as 2'-dATP, which had an IC50 of 30-50 microM versus the stimulation of CDP and GDP reduction by 2.0 mM ATP.