Antibodies against DNA-psoralen crosslink recognize unique conformation

• Published in: Biochimica et biophysica acta Vol. 1073; no. 3; pp. 509 - 513
• Main Authors: Hasan, Rashid, Ali, Asif, Ali, Rashid
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 09.04.1991; Elsevier
• Subjects: Animals; Anti-DNA antibody; anti-DNA-psoralen antibody; Antibodies, Antinuclear - biosynthesis; Antibodies, Antinuclear - immunology; Antibody Specificity; Antigen-antibody reactions, antigen-antibody complexes, antibody-complement and others. Study of affinity. Antigen presentation; Biological and medical sciences; Chromatography, DEAE-Cellulose; DNA - immunology; DNA - radiation effects; DNA adduct; DNA crosslink; DNA-psoralen; Enzyme-Linked Immunosorbent Assay; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Furocoumarins - immunology; Furocoumarins - radiation effects; Humans; Immunoglobulin G - immunology; Lupus Erythematosus, Systemic - immunology; Macromolecular Substances; Molecular immunology; Nucleic Acid Conformation; Polydeoxyribonucleotides - immunology; Psoralen; Rabbits; Ultraviolet Rays; Psoralen; DNA crosslink; PUVA; DNA adduct; DNA-psoralen; nDNA; Anti-DNA antibody; anti-DNA-psoralen antibody; dDNA; Immunization; Intercalating agent; Antibody; Rabbit; Molecular interaction; Lagomorpha; Vertebrata; Mammalia; Type specificity; Immunogenicity; Affinity chromatography; DNA; Furo coumarin derivatives; Molecular complex; ELISA assay; Molecular adduct; Conformation
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(91)90223-4

The DNA-psoralen crosslink induced precipitating antibodies in rabbits with a titer of 1:102400 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.