title: Physicochemical properties of the triiodothyronine nuclear receptor from tadpole liver, intestine and tail fin.
abstract: The binding of triiodothyronine (T3) to tadpole liver, intestine, and tail fin nuclei was consistent with a single class of binding sites. The KD for the binding of T3 to isolated nuclei from the liver (1.02 nM), intestine (1.40 nM), and tail fin (0.831 nM) nuclei were not significantly different. The number of binding sites for T3 in the nuclei isolated from each tissue were also not significantly different. Sucrose gradient centrifugation of the salt-extracted nuclear T3-receptor complex revealed that the S20,w was not significantly different for the complex from the liver (3.7 S), intestine (3.9 S), or tail fin (3.9 S). Similarly, the Stokes radii of the complex from the liver (3.65 nm), intestine (3.84 nm), and tail fin (3.99 nm) were not significantly different. Molecular weights of 57,000, 64,000, and 67,000 were calculated from the sedimentation coefficients and Stokes radii for the T3-receptor complex from the liver, intestine, and tail fin, respectively. The similarity of the physicochemical properties of the T3-receptor complex from each of the tissues studied is consistent with the hypothesis that the same receptor is capable of inducing tissue-specific biochemical changes.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008675:Metamorphosis, Biological; D008970:Molecular Weight; D009928:Organ Specificity; D011487:Protein Conformation; D011892:Rana catesbeiana; D011988:Receptors, Thyroid Hormone / Q000302:isolation & purification* / Q000378:metabolism; D012867:Skin / Q000378:metabolism*; D013623:Tail
chemical_list: D011988:Receptors, Thyroid Hormone