Related Experiment Video
Updated: Jul 10, 2026

Demonstration of the Sequence Alignment to Predict Across Species Susceptibility Tool for Rapid Assessment of Protein Conservation
Published on: February 10, 2023
Characterization of thyroid hormone receptor alpha (TRalpha)-specific analogs with varying inner- and outer-ring
Cory A Ocasio1, Thomas S Scanlan
1Chemistry and Chemical Biology Graduate Program, University of California-San Francisco, 600 16th Street, San Francisco, CA 94143-2280, USA.
Abstract:
Analogs of the TRalpha-specific thyromimetic CO23 were synthesized and analyzed in vitro using competitive binding and transactivation assays. Like CO23, all analogs bind to both thyroid hormone receptor subtypes with about the same affinity; however, modification of CO23 by derivatization of the 3' position of the outer-ring or replacement of the inner-ring iodides with bromides attenuates binding. Despite lacking a preference in binding to TRalpha, all analogs display TRalpha-specificity in transactivation assays using U2OS and HeLa cells. At best, several agonists exhibit an approximately 6-12-fold preference in transactivation when tested with TRalpha in HeLa cells. One analog, CO24, showed in vivo TRalpha-specific action in a tadpole metamorphosis assay.
More Related Videos
10:16Autoradiography as a Simple and Powerful Method for Visualization and Characterization of Pharmacological Targets
Published on: March 12, 2019
09:07Detecting the Ligand-binding Domain Dimerization Activity of Estrogen Receptor Alpha Using the Mammalian Two-Hybrid Assay
Published on: December 19, 2018
Related Concept Videos
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
Intracellular Hormone Receptors
Adrenergic Antagonists: Chemistry and Classification of ɑ-Receptor Blockers
Nonselective α-blockers: Nonselective α-blockers contain haloalkylamine or imidazoline moieties. Phenoxybenzamine, with a haloalkylamine...
Types of Hormones
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3