The pro-enkephalin A derivative, peptide E, is centrally processed to active fragments

Recent evidence has indicated that all known opioid peptides are derived from one of 3 large precursor proteins, pro-opiomelanocortin, proenkephalin A, and proenkephalin B. The isolation and characterization of enkephalin-related peptides, derived from proenkephalin A, such as peptide E, BAM 22P, and BAM12P resulted from the discovery of enkephalin-like immunoreactivity within the adrenal medulla. Previous studies in our laboratory on the pro-opiomelanocortin derived peptide, β-endorphin, has shown that the presence of pairs of basic amino acids along this high molecular weight precursor leads to specific enzymatic cleavages by membrane bound enzymes into active peptide fragments. Based on the studies we chose to investigate if the proenkephalin A derivative, peptide E, is also processed centrally to active fragments.