title: Competitive inhibition of uracil DNA glycosylase by a modified nucleotide whose triphosphate is a substrate for DNA polymerase.
abstract: Base excision repair (BER) enzymes are attractive targets for antiviral and anticancer agents. A number of nucleotides and nucleotide analogues are potent competitive inhibitors of BER glycosylases when they are incorporated into synthetic oligonucleotides. However, these molecules often are not substrates for DNA polymerases, which limits their utility in cells and as potential therapeutic agents. 1'-Cyano-2'-deoxyuridine (CNdU) is a nanomolar competitive inhibitor of uracil DNA glycosylase. In addition, the respective nucleotide triphosphate is accepted as a substrate by the Klenow fragment (exo(-)) of DNA polymerase I from E. coli. This is the first competitive inhibitor of UDG that is incorporated into DNA by Klenow exo(-), a model replicative polymerase. 1'-Cyano-2'-deoxyuridine (CNdU) and related molecules may prove useful as a new family of therapeutic or experimental agents that target DNA repair by using the cells' polymerase(s) to incorporate them into DNA. A potential benefit of such a mechanism is that multiple incorporations can occur for longer DNA molecules leading to amplification of the inhibitory effect beyond that seen here with short DNA duplexes.
authors.affiliation: Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
authors.forename: Haidong
authors.initials: H
authors.lastname: Huang
authors.forename: James T
authors.initials: JT
authors.lastname: Stivers
authors.forename: Marc M
authors.initials: MM
authors.lastname: Greenberg
mesh_terms: D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D008958:Models, Molecular; D015394:Molecular Structure; D009711:Nucleotides / Q000737:chemistry* / Q000378:metabolism*; D010710:Phosphates / Q000737:chemistry*; D013379:Substrate Specificity; D013816:Thermodynamics; D044366:Transition Temperature; D051981:Uracil-DNA Glycosidase / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D009711:Nucleotides; D010710:Phosphates; D004259:DNA-Directed DNA Polymerase; D051981:Uracil-DNA Glycosidase