title: Cross-linking of 2-deoxyribonolactone and its beta-elimination product by base excision repair enzymes.
abstract: 2-Deoxyribonolactone (3) is produced in DNA as a result of reaction with a variety of DNA damaging agents. The lesion undergoes beta-elimination to form a second metastable electrophilic product (4). In this study, DNA containing 2-deoxyribonolactone (3) and its beta-elimination product (4) are generated at specific sites using a photolabile nucleotide precursor. 2-Deoxyribonolactone is not incised by any of the 8 AP lyases tested. One enzyme, Escherichia coli endonuclease III, cross-links to 3, and the lesion strongly inhibits excision of typical abasic sites by this enzyme. Two of the enzymes, FPG and NEIL1 known to cleave normal abasic sites (1) by effecting beta,delta-elimination form cross-links to the butenolide lesion (4). The observed results are ascribable to characteristics of the enzymes and the lesions. These enzymes are also important for the removal of oxidative base lesions. These results suggest that high concentrations of 3 and 4 may exert significant effects on the repair of normal AP site and oxidative base lesions in cells by reducing the cellular activity of these BER enzymes either via cross-linking or competing with binding to the BER enzymes.
authors.affiliation: Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Kroeger
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Yoke Wah
authors.initials: YW
authors.lastname: Kow
authors.forename: Marc M
authors.initials: MM
authors.lastname: Greenberg
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives; D001665:Binding Sites; D019757:Carbon-Oxygen Lyases / Q000037:antagonists & inhibitors / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004249:DNA Damage; D004260:DNA Repair; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043382:DNA-Formamidopyrimidine Glycosylase; D043224:Deoxyribonuclease (Pyrimidine Dimer); D004706:Endodeoxyribonucleases / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D006801:Humans; D006868:Hydrolysis; D009699:N-Glycosyl Hydrolases / Q000737:chemistry; D009692:Nucleic Acid Heteroduplexes / Q000037:antagonists & inhibitors / Q000737:chemistry; D013400:Sugar Acids / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; D005663:Furans; D009692:Nucleic Acid Heteroduplexes; D013400:Sugar Acids; C056405:2,4,5-trihydroxypentanoic acid gamma-lactone; C004511:butenolide; D004706:Endodeoxyribonucleases; D043224:Deoxyribonuclease (Pyrimidine Dimer); C106403:NTH protein, E coli; D009699:N-Glycosyl Hydrolases; D043382:DNA-Formamidopyrimidine Glycosylase; C468610:DNA-formamidopyrimidine glycosylase, E coli; D019757:Carbon-Oxygen Lyases; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D015107:4-Butyrolactone