title: The oxidative damage to the human telomere: effects of 5-hydroxymethyl-2'-deoxyuridine on telomeric G-quadruplex structures.
abstract: As part of the genome, human telomeric regions can be damaged by the chemically reactive molecules responsible for oxidative DNA damage. Considering that G-quadruplex structures have been proven to occur in human telomere regions, several studies have been devoted to investigating the effect of oxidation products on the properties of these structures. However only investigations concerning the presence in G-quadruplexes of the main oxidation products of deoxyguanosine and deoxyadenosine have appeared in the literature. Here, we investigated the effects of 5-hydroxymethyl-2'-deoxyuridine (5-hmdU), one of the main oxidation products of T, on the physical-chemical properties of the G-quadruplex structures formed by two human telomeric sequences. Collected calorimetric, circular dichroism and electrophoretic data suggest that, in contrast to most of the results on other damage, the replacement of a T with a 5-hmdU results in only negligible effects on structural stability. Reported results and other data from literature suggest a possible protecting effect of the loop residues on the other parts of the G-quadruplexes.
authors.affiliation: Dipartimento di Farmacia, Università degli Studi di Napoli "Federico II", Via D. Montesano 49, I-80131 Napoli, Italy. galeone@unina.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Virgilio
authors.forename: Veronica
authors.initials: V
authors.lastname: Esposito
authors.forename: Luciano
authors.initials: L
authors.lastname: Mayol
authors.forename: Concetta
authors.initials: C
authors.lastname: Giancola
authors.forename: Luigi
authors.initials: L
authors.lastname: Petraccone
authors.forename: Aldo
authors.initials: A
authors.lastname: Galeone
mesh_terms: D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D054856:G-Quadruplexes; D006801:Humans; D009691:Nucleic Acid Denaturation; D010084:Oxidation-Reduction; D016615:Telomere / Q000737:chemistry*; D013696:Temperature; D013936:Thymidine / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: C018080:5-hydroxymethyl-2'-deoxyuridine; D013936:Thymidine