Record Display for the EPA National Library Catalog

RECORD NUMBER: 117 OF 689

OLS Field Name OLS Field Data
Main Title Characterization of the Ah Receptor.
Author Safe, S. H. ;
CORP Author Texas A and M Univ., College Station. Dept. of Veterinary Physiology and Pharmacology.;Health Effects Research Lab., Cincinnati, OH.
Publisher Oct 88
Year Published 1988
Report Number EPA-R-823626; EPA/600/1-88/006;
Stock Number PB89-118657
Additional Subjects Toxicity ; Industrial wastes ; In vitro analysis ; Reaction kinetics ; Enthalpy ; Sense organs ; Chemical reactions ; Mathematical models ; Carcinogens ; Risk assessment
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB89-118657 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 03/14/1989
Collation 32p
Abstract
The rat liver cytosolic receptor protein containing the Ah-receptor protein was purified and studied using a photochemical assembly of 2,3,7,8-TCDD. The unbound receptor protein rapidly lost its capacity to bind 2,3,7,8-TCDD; however, the 2,3,7,8-TCDD bound Ah receptor did not readily dissociate, probably reflecting the high potency and persistence of the toxicity of 2,3,7,8-TCDD. Results are based on a new one-step methodology which allows activation parameters to be calculated directly from raw experimental measurements, which allows the uncertainty in the activation enthalpy to be obtained unambiguously. The enthalpies of activation for both the formation and the interaction of the receptor-ligand complex are the same within the statistical uncertainty. This led to a kinetic model in which the receptor was activated to an intermediate followed by competitive degradation of the unoccupied receptor and formation of the receptor-ligand complex, both of these latter steps being fast compared with the first.