title: The specificity of antimorphine and antimeperidine antibodies and their reactivity with opioid peptides.
abstract: The specificity of antimorphine and antimeperidine antisera was measured by competitive displacement of immunizing radiolabeled haptens. Antimorphine antisera demonstrated a high degree of specificity for a conformation of the phenylpiperidine moiety contained within the structures of morphine and its congeners of the morphinan and benzomorphan series. Antimeperidine antisera demonstrated a high degree of specificity for a different conformation of the phenylpiperidine moiety represented within the structures of meperidine and its semisynthetic derivatives. The reactivity of methionine- and leucine-enkephalin, several synthetic enkephalin analogs, and alpha- and beta-endorphin with the antibodies was tested using purified immunoglobulin G in order to avoid serum-induced proteolysis. No significant cross-reactivity of antimorphine antibodies with any of the opioid peptides was detected. All of the opioid peptides tested exhibited weak but immunologically specific cross-reactivity with antimeperidine antibodies. These findings suggest that conformations analogous to the phenylpiperidine moiety in morphine as have been proposed for [Tyr1] in opioid peptides do not appear to be present as measured by immunochemical methods. A conformation with weak stereochemical similarity to the phenylpeperidine moiety in meperidine does appear to be present. The possible homologies between [Phe4] of opioid peptides, meperidine and hydrophobic side chains of certain oripavine derivatives are discussed.
mesh_terms: D000918:Antibody Specificity; D001667:Binding, Competitive; D003429:Cross Reactions; D004355:Drug Stability; D004723:Endorphins / Q000276:immunology*; D004745:Enkephalins / Q000276:immunology*; D007074:Immunoglobulin G / Q000378:metabolism; D008614:Meperidine / Q000276:immunology*; D008968:Molecular Conformation; D009020:Morphine / Q000276:immunology*; D010880:Piperidines
chemical_list: D004723:Endorphins; D004745:Enkephalins; D007074:Immunoglobulin G; D010880:Piperidines; D009020:Morphine; D008614:Meperidine