1. Synthesis and characterization of CGP-12177-NBD: a fluorescent beta-adrenergic receptor probe
- Author
-
Richard C. Cantrill, Ernst J.M. Helmreich, Larry D. Ward, Knut A. Jaeggi, and Helmuth Heithier
- Subjects
Turkeys ,Stereochemistry ,Adrenergic beta-Antagonists ,Quantum yield ,Biochemistry ,Cell Line ,Propanolamines ,chemistry.chemical_compound ,Receptors, Adrenergic, beta ,Animals ,Receptor ,Cells, Cultured ,Fluorescent Dyes ,Oxadiazoles ,Chloroform ,Erythrocyte Membrane ,General Medicine ,Ligand (biochemistry) ,Fluorescence ,Kinetics ,Membrane ,4-Chloro-7-nitrobenzofurazan ,Spectrometry, Fluorescence ,chemistry ,Cell culture ,Solvents ,sense organs ,A431 cells - Abstract
The synthesis and properties of a fluorescent derivative of the hydrophilic beta-adrenergic antagonist CGP-12177 are described. The fluorescence of the NBD derivative of CGP-12177 (CGP-NBD) is extremely sensitive to its environment, the quantum yield increasing 23-fold upon transfer from water to acetonitrile. This property of CGP-NBD was taken into account and a procedure was developed using quantitative chloroform extraction of ligand for the measurement of CGP-NBD bound specifically to beta-receptors on A431.E3 membranes. The fluorescent NBD-derivative of CGP-12177 bound strongly and specifically to A431 cells, a KD of 3.9 x 10(-10) M being measured; the specific binding represented 63% of the total binding at a concentration of 1 x 10(-8) M (256 x KD). A431.E3 cells were used for the binding studies since they gave consistently higher receptor numbers when compared with the native strain. A maximal number of 47,000 sites/cell and a KD of 100 pM were measured with CGP-12177 on adhered cells. The receptor number was strongly dependent upon cell density with only 3000 sites/cell being measured in suspension at confluence.
- Published
- 1988