title: The binding of thyroid hormone receptors to DNA.
abstract: The behaviour of tri-iodothyronine (T3)- and thyroxine (T4)-receptor complexes when bound to native DNA-cellulose is reported. Equal and large proportions of both T3- and T4-receptor complexes bind to DNA but although T3-receptor complexes are 99% recoverable by 0.5 M NaCl buffer elution, only 60-70% of the T4-receptor complexes are regained. The balance appears as free T4, apparently released as the T4-receptor complexes bind to the DNA whilst the corresponding receptor remains bound. This effect is independent of T4-receptor complex/DNA ratio up to ca. 4 fmol/micrograms DNA, of the presence of an equal amount of unoccupied receptor and of an eight-fold concentration range of both T4-receptor complex and DNA at a fixed ratio, in the cellulose matrix. Pre-formed receptor-DNA material, likewise, only accepts some 60% of the expected quantity of T4 whereas the capacity for T3 appears to be similar to that of free receptors.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002846:Chromatography, Affinity / Q000379:methods; D004247:DNA / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000302:isolation & purification / Q000378:metabolism*; D011988:Receptors, Thyroid Hormone; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism*
chemical_list: D011956:Receptors, Cell Surface; D011988:Receptors, Thyroid Hormone; D014284:Triiodothyronine; D004247:DNA; D013974:Thyroxine