Interaction between antibodies to Z-form deoxyribonucleic acid and double-stranded polynucleotides.
Antibodies to Z-DNA have been elicited in rabbits immunized with chloro(diethylenetriamine)platinum(II)chloride (Cl2dienPt) modified poly(dG-dC).poly(dG-dC). Under physiological conditions this polynucleotide in which 12% of the bases were substituted is in the Z form. The antibodies are mainly immunoglobulins G as shown by gel filtration of the antiserum and by ultracentrifugation of the antibodies purified on a Sepharose--poly(dG-dC).poly(dG-dC) column. From the quantitative precipitin curve, it is concluded that each binding site of the antibody covers four nucleotide residues. The Z-form DNA-antibody complex is stabilized by electrostatic interactions. There was no interaction between poly(dI-br5dC).poly(dI-br5dC) in the Z form and the antibodies, which strongly suggests that the exocyclic amino group of guanine residues in Z-poly(dG-dC).poly(dG-dC) interacts with the antibody binding site. The modification of poly(dG-dC).poly(dG-dC) by 2-(acetylamino)fluorene residues decreases but does not prevent the binding to the antibodies. It is also shown that the polynucleotide poly(dG-br5dC).poly(dG-br5dC) adopts the Z form over a large range of salt concentration [5 mM tris(hydroxymethyl)aminomethane hydrochloride, pH 7.5, to 3 M NaCl].
D000818:Animals; D000906:Antibodies / Q000276:immunology* / Q000302:isolation & purification; D001666:Binding Sites, Antibody; D004247:DNA / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D009690:Nucleic Acid Conformation; D009994:Osmolar Concentration; D011089:Polydeoxyribonucleotides / Q000276:immunology; D011119:Polynucleotides / Q000276:immunology*; D011817:Rabbits; D011863:Radioimmunoassay; D013696:Temperature
D000906:Antibodies; D007074:Immunoglobulin G; D011089:Polydeoxyribonucleotides; D011119:Polynucleotides; C019530:poly(dC-dG); D004247:DNA