title: Unique poly(dA).poly(dT) B'-conformation in cellular and synthetic DNAs.
abstract: Poly(dA).poly(dT), but not B-form DNA, is specifically recognized by experimentally induced anti-kinetoplast or anti-poly(dA).poly(dT) immunoglobulins. Antibody binding is completely competed by poly(dA).poly(dT) and poly(dA).poly(dU) but not by other single- or double-stranded DNA sequences in a right-handed B-form. Antibody interaction with poly(dA).poly(dT) depends on immunoglobulin concentration, incubation time and temperature, and is sensitive to elevated ionic strengths. Similar conformations, for example, (dA)4-6 X (dT)4-6, in the kinetoplast DNA of the parasite Leishmania tarentolae are also immunogenic and induce specific anti-poly(dA).poly(dT) antibodies. These antibody probes specifically recognize nuclear and kinetoplast DNA in fixed flagellated kinetoplastid cells as evidenced by immunofluorescence microscopy. Anti-poly(dA).poly(dT) immunofluorescence is DNase-sensitive and competed by poly(dA).poly(dT), but not other classical double-stranded B-DNAs. Thus, these unique cellular B'-DNA helices are immunogenic and structurally similar to synthetic poly(dA).poly(dT) helices in solution.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D005260:Female; D007136:Immunoglobulins / Q000276:immunology; D009690:Nucleic Acid Conformation; D011067:Poly dA-dT / Q000276:immunology; D011089:Polydeoxyribonucleotides / Q000276:immunology; D011817:Rabbits; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D007136:Immunoglobulins; D011089:Polydeoxyribonucleotides; D011067:Poly dA-dT; D012965:Sodium Chloride