title: [Interaction of SV40 T-antigen with homologous and heterologous DNA].
abstract: Using the DNA filter binding assay, the effects of ionic strength and pH on SV40 T-antigen interaction with viral DNA were studied. The apparent association constants for T-antigen binding to SV40 DNA in Scatchard coordinates in the presence of 40 mM NaCl are equal to 0.67 . 10(6) M-1 (pH 6.0) and 0.86 x 10(7) M-1 (pH 7.4). These data indicate that the interaction between T-antigen and SV40 DNA is more specific at pH 7.4. The coincident values of association constants for T-antigen binding to viral and cellular DNAs (Ka = 0.9 x 10(7) M-1 for cellular DNA) at pH 7.4 and the absence of competition between the two DNA species upon binding with T-antigen suggest that viral and cellular DNAs possess similar sites for T-antigen binding. Denatured DNA competes with viral DNA only at pH 6.0, when the T-antigen--SV40 DNA interaction is less specific.
mesh_terms: D000936:Antigen-Antibody Complex; D000951:Antigens, Neoplasm / Q000276:immunology*; D000956:Antigens, Viral / Q000276:immunology*; D000957:Antigens, Viral, Tumor; D002472:Cell Transformation, Viral; D004247:DNA / Q000276:immunology*; D004279:DNA, Viral / Q000276:immunology*; D007700:Kinetics; D013539:Simian virus 40 / Q000276:immunology*
chemical_list: D000936:Antigen-Antibody Complex; D000951:Antigens, Neoplasm; D000956:Antigens, Viral; D000957:Antigens, Viral, Tumor; D004279:DNA, Viral; D004247:DNA
vernacular_title: Vzaimodeĭstvie T-antigena virusa SV-40 s gomologichnoĭ i geterologichnymi DNK.