title: Analysis of human DNA-arginine photoadduct modified with peroxynitrite.
abstract: The aim of the study is the biochemical characterization of human DNA modified with arginine and peroxynitrite. In the present study, DNA was isolated from human blood cells and its adduct was formed with one of the amino acid, arginine. The DNA-arginine adduct was then modified with peroxynitrite, a reactive nitrogen species. The modified DNA adduct was characterized by ultraviolet (UV) absorption spectroscopy, thermal melting profile, and electrophoresis studies. UV spectroscopic analysis of the photoadduct showed hyperchromicity, indicating the formation of single-strand breaks and photomodification. Thermal denaturation studies of DNA-arginine adduct and peroxynitrite-modified adduct showed a decrease in the temperature (T(m)) value by 4.5°C and an increase in the T(m) of 8°C, respectively. Peroxynitrite modification is evident by an increase in the T(m) value and a change in the migration pattern of native and modified photoadducts on agarose gel electrophoresis. The DNA-arginine and peroxynitrite-modified photoadducts could have important implications in various pathophysiological and immunopathological conditions.
authors.affiliation: Department of Biochemistry and Physiology, Oman Medical College, Sohar, Sultanate of Oman.
authors.forename: Rizwan
authors.initials: R
authors.lastname: Ahmad
authors.forename: Neha
authors.initials: N
authors.lastname: Yadav
authors.forename: Khyati
authors.initials: K
authors.lastname: Chaudhary
authors.forename: Thomas
authors.initials: T
authors.lastname: Heming
authors.forename: Haseeb
authors.initials: H
authors.lastname: Ahsan
mesh_terms: D001120:Arginine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D018736:DNA Adducts / Q000032:analysis / Q000737:chemistry*; D006801:Humans; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D030421:Peroxynitrous Acid / Q000737:chemistry*; D013696:Temperature
chemical_list: D018736:DNA Adducts; D030421:Peroxynitrous Acid; D004247:DNA; D001120:Arginine