High ligand-receptor interactions

CEP receptors exhibit high ligand affinity and saturation kinetics for ligand binding. The protein portion of these complexes appears to participate in ligand-receptor interaction since protease treatment of aortic CEP complexes abolishes uptake [24]. Binding is competitively inhibited by polyanions in a pattern similar to the inhibition observed for the acetyl-LDL receptor [24]. However, the CEP receptor appears to be distinct from the acetyl-LDL receptor since their ligands do not mutually compete for uptake [24]. 

The most extensively studied agonists are the halogenated aromatic hydrocarbons such as TCDD, polychlorinated biphenyls, and polychlorinated dibenzofurans as well as PAHs such as benzo[a]pyrene and 3-MC. One of the highest affinity ligands of the AHR and the most potent inducer of CYPlAl expression is TCDD. As the result of this ligand-receptor interaction, exposure to TCDD produces a wide variety of toxic effects that are species- and tissue-specific. The response to TCDD is due to the fact that TCDD has a remarkably high affinity for the AHR (on the order of 10 M, and that this ligand is... 

---