FY91 EPSCOR Structure-Activity Relationships of Chlorinated Alicyclic Compoundsin Catfish

摘要

The scientific goal of this project has been to extend the quantitative structure-activity relationship study of the parent grant, 91-0338, to catfish brain membranes. The binding of 35St-butylbicyclophosphorothionate (TBPS) to the Y-aminobutyric acid (GABA) receptor was studied to characterize the binding affinity of the receptor, and to determine the competition of a series of chlorinated alicycic compounds including chlorinated cyclodiene insecticides and related compounds. These ligand binding studies have indicated the presence of two populations of receptors, with calculated Kd's of 26.10 and 1128.98 nM and Bmax's of 2.95 and 5.14 pmol/mg protein, respectively. All chlorinated alicyclic compounds tested have inhibited TBPS binding except mirex. The IC50's cover a range of 19.97 to 21,177 nM. The IC50's generally correlate with the acute toxicity level for those insecticides reported in the literature.