title: A simple, high-yield synthesis of DNA duplexes containing a covalent, thermally cleavable interstrand cross-link at a defined location.
abstract: Interstrand DNA-DNA cross-links are highly toxic to cells because these lesions block the extraction of information from the genetic material. The pathways by which cells repair cross-links are important, but not well understood. The preparation of chemically well-defined cross-linked DNA substrates represents a significant challenge in the study of cross-link repair. Here a simple method is reported that employs "post-synthetic" modifications of commercially available 2'-deoxyoligonucleotides to install a single cross-link in high yield at a specified location within a DNA duplex. The cross-linking process exploits the formation of a hydrazone between a non-natural N(4) -amino-2'-deoxycytidine nucleobase and the aldehyde residue of an abasic site in duplex DNA. The resulting cross-link is stable under physiological conditions, but can be readily dissociated and re-formed through heating-cooling cycles.
authors.affiliation: Department of Chemistry, University of Missouri, Columbia, MO 65211 (USA).
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Gamboa Varela
authors.affiliation: Department of Chemistry, University of Missouri, Columbia, MO 65211 (USA). gatesk@missouri.edu.|Department of Biochemistry, University of Missouri, Columbia, MO 65211 (USA). gatesk@missouri.edu.
authors.forename: Kent S
authors.initials: KS
authors.lastname: Gates
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry*; D004247:DNA / Q000138:chemical synthesis* / Q000737:chemistry*; D006835:Hydrazones / Q000737:chemistry*; D015394:Molecular Structure; D009690:Nucleic Acid Conformation
chemical_list: D003432:Cross-Linking Reagents; D006835:Hydrazones; D004247:DNA
keywords: DNA cross-links; abasic sites; hydrazones; nucleic acids