A monoclonal antibody specific for a dynorphin precursor.

Murine monoclonal antibodies were produced against dynorphin-32 (D32), a naturally occurring opioid peptide containing the sequence of dynorphin A (Dyn A) at its amino terminus, followed by Lys-Arg, then by the sequence of dynorphin B (Dyn B). Initial characterization using an enzyme-linked immunosorbent assay revealed that one clone (17.M) recognized D32 but not Dyn A or Dyn B. A solid-phase radioimmunoassay using 125I-labeled antibody 17.M was developed and showed a maximum sensitivity of 45 fmol for synthetic D32. Dyn B crossreacted only 0.05%; Dyn A and other related opioid peptides crossreacted less than 0.001%. Immunoreactive D32 was detected in extracts of rat brain and anterior pituitary but not neurointermediate lobe of pituitary. The unique specificity of monoclonal antibody 17.M should make it useful in investigations of the differential localization and release of Dyn A and Dyn B and the precursor D32.