title: Discovery and synthesis of new UV-induced intrastrand C(4-8)G and G(8-4)C photolesions.
abstract: UV irradiation of cellular DNA leads to the formation of a number of defined mutagenic DNA lesions. Here we report the discovery of new intrastrand C(4-8)G and G(8-4)C cross-link lesions in which the C(4) amino group of the cytosine base is covalently linked to the C(8) position of an adjacent dG base. The structure of the novel lesions was clarified by HPLC-MS/MS data for UV-irradiated DNA in combination with chemical synthesis and direct comparison of the synthetic material with irradiated DNA. We also report the ability to generate the lesions directly in DNA with the help of a photoactive precursor that was site-specifically incorporated into DNA. This should enable detailed chemical and biochemical investigations of these lesions.
authors.affiliation: Center for Integrated Protein Science (CIPS(M)) at the Department of Chemistry, Ludwig-Maximilians-University Munich , Butenandtstrasse 5-13, 81377 Munich, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Münzel
authors.forename: Claudia
authors.initials: C
authors.lastname: Szeibert
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Glas
authors.forename: Daniel
authors.initials: D
authors.lastname: Globisch
authors.forename: Thomas
authors.initials: T
authors.lastname: Carell
mesh_terms: D003596:Cytosine / Q000737:chemistry; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D055668:Photochemical Processes; D014466:Ultraviolet Rays
chemical_list: D003596:Cytosine; D004247:DNA