Experimental values of the ionization constants for L-3,5-di-iodotyrosine and a model for ionic interactions of thyroid hormone (T3) and its nuclear receptor
Date
1989
Authors
Gent W.L.
Wilson B.D.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Ionization characteristics of L-3,5-di-iodotyrosine have been measured under various conditions. These data, which correct an erroneous report of pK3 in the literature, have been used to estimate the ionization constants of the thyroid hormone L-3',3,5-tri-iodothyronine (T3). On this basis a reinterpretation has been made of the pH-dependent binding of the hormone to its solubilized rat liver nuclear receptor (Wilson BD and Gent WL, Biochem J 232: 663-667, 1985). The interaction may depend on the ionization of the phenolic group of T3 and an acidic group (pK'7.6) in the receptor site, leading to the formation of a hydrogen bond between the two groups. The changes of the number of binding sites with pH must then result independently from alterations in the conformation of the receptor protein.
Description
Keywords
diiodotyrosine, receptor, animal cell, drug receptor binding, drug structure, liver, liver cell nucleus, nonhuman, ph, priority journal, rat, Diiodothyronines, Hydrogen-Ion Concentration, Ions, Models, Theoretical, Nuclear Proteins, Receptors, Thyroid Hormone, Structure-Activity Relationship, Thyronines, Triiodothyronine
Citation
Biochemical Pharmacology
38
2
38
2