Antibodies against arylcyclohexylamines and their similarities in binding specificity with the phencyclidine receptor.
Rabbit antibodies were generated against five unique epitopes of phencyclidine (PCP)-like molecules to determine the molecular requirements for arylcyclohexylamine binding to the PCP receptor. Three of the haptens contained the three ring structures of PCP. A fourth hapten was synthesized from a derivative of the highly potent PCP analog, 1-[1-(2-thienyl)cyclohexyl]piperidine. The fifth hapten, 5-[N-(1'-phenylcyclohexyl)amino]pentanoic acid, was used as a haptenic model for N-ethyl-1-phenylcyclohexylamine, one of the most potent arylcyclohexylamines. These haptens were bound covalently to bovine serum albumin and were then used as antigens to immunize rabbits. The affinities and cross-reactivity patterns of the resulting five antibodies were studied in a [3H]PCP radioimmunoassay using standard curves of various arylcyclohexylamines. The dissociation constants ranged from 1.9 to 51.6 nM. From the average IC50 values of the radioimmunoassay dose-response curves, the relative potency of each ligand to PCP was determined. Least-squares linear regression was used to correlate these data with relative potency data from two [3H]PCP receptor binding assays and a PCP drug discrimination assay in the rat. Only relative potency data from the anti-5[N-(1'-phenylcyclohexyl)amino]pentanoic acid antibody showed a significant correlation with data from the three pharmacological studies (r2 = 0.80, 0.57 and 0.78, respectively; p less than .05 in all cases). These data indicated the 5-[N-(1'-phenylcyclohexyl)amino]pentanoic acid hapten contained the pharmacologically active features needed for arylcyclohexylamine binding to the PCP receptor.
Owens
S M
SM
Department of Pharmacology and Interdisciplinary Toxicology, University of Arkansas for Medical Sciences, Little Rock.
Zorbas
M
M
Lattin
D L
DL
Gunnell
M
M
Polk
M
M
D000818:Animals; D000918:Antibody Specificity; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D003514:Cyclohexylamines / Q000276:immunology / Q000378:metabolism*; D000939:Epitopes / Q000032:analysis; D006241:Haptens / Q000138:chemical synthesis / Q000276:immunology; D010622:Phencyclidine / Q000031:analogs & derivatives / Q000378:metabolism*; D011817:Rabbits; D011863:Radioimmunoassay; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D017478:Receptors, Phencyclidine; D013329:Structure-Activity Relationship; D014316:Tritium
D003514:Cyclohexylamines; D000939:Epitopes; D006241:Haptens; D017981:Receptors, Neurotransmitter; D017478:Receptors, Phencyclidine; D014316:Tritium; D010622:Phencyclidine