title: Antibodies against DNA-psoralen crosslink recognize unique conformation.
abstract: The DNA-psoralen crosslink induced precipitating antibodies in rabbits with a titer of 1:102,400 by direct binding ELISA. The antiserum showed considerable binding with Z-DNA and calf thymus DNA brominated under high salt concentration which has been shown to attain Z-/analogous conformation. Inhibition experiments substantiated the results of direct binding assay. However, the affinity purified IgG showed high degree of specificity for the immunogen and did not recognize nDNA, Z-DNA and brominated DNA as inhibitor. Poly(dG.dC).poly(dG.dC)-psoralen photoadduct was found to be inhibitory. These results indicate that the antibodies are probably recognizing the unique conformation at the site of psoralen crosslinking. The DNA-psoralen crosslink showed significant binding with SLE sera known to have high levels of anti-native DNA antibodies. Affinity purified SLE-IgG in a competition assay pointed out the autoantibody recognition of altered conformation of DNA-psoralen crosslink.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Aligarh Muslim University, India.
authors.forename: R
authors.initials: R
authors.lastname: Hasan
authors.forename: A
authors.initials: A
authors.lastname: Ali
authors.forename: R
authors.initials: R
authors.lastname: Ali
mesh_terms: D000818:Animals; D000974:Antibodies, Antinuclear / Q000096:biosynthesis / Q000276:immunology*; D000918:Antibody Specificity; D002848:Chromatography, DEAE-Cellulose; D004247:DNA / Q000276:immunology* / Q000528:radiation effects; D004797:Enzyme-Linked Immunosorbent Assay; D011564:Furocoumarins / Q000276:immunology* / Q000528:radiation effects; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D046911:Macromolecular Substances; D009690:Nucleic Acid Conformation; D011089:Polydeoxyribonucleotides / Q000276:immunology; D011817:Rabbits; D014466:Ultraviolet Rays
chemical_list: D000974:Antibodies, Antinuclear; D011564:Furocoumarins; D007074:Immunoglobulin G; D046911:Macromolecular Substances; D011089:Polydeoxyribonucleotides; C016681:poly(dG).poly(dC); D004247:DNA