%0 Journal Article %A ROBERT A. LIPPER %A SUSAN M. MACHKOVECH %A JOHN C. DRACH %A WILLIAM I. HIGUCHI %T Inhibition of Drug Metabolism by a Prodrug: 9-β-D-Arabinofuranosyladenine 5'-Valerate as an Inhibitor of Adenosine Deaminase %D 1978 %J Molecular Pharmacology %P 366-369 %V 14 %N 2 %X 9-β-D-Arabinofuranosyladenine 5'-valerate (ara-A-5'-valerate), a bioreversible derivative or prodrug of the antiviral agent 9-β-D-arabinofuranosyladenine (ara-A), was shown to be a competitive inhibitor of calf intestinal adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4). With ara-A as the substrate, apparent Km and Ki values were 110 µM and 11 µM, respectively, at 37°. Ara-A-5'-valerate is not subject to adenosine deaminase-catalyzed deamination, and it is more water-soluble and more lipophilic than ara-A. ACKNOWLEDGMENTS We thank Drs. D. C. Baker, A. J. Giazko, and T. H. Haskell of Warner-Lambert/Parke-Davis Pharmaceutical Research Division for their generosity in supplying compounds used in these studies. %U https://molpharm.aspetjournals.org/content/molpharm/14/2/366.full.pdf