title: Immunochemical study on PHI/PHM with use of synthetic peptides.
abstract: We have synthesized PHI and PHM (human PHI) as well as their fragments, PHI (1-6), PHI (1-15), PHI (14-19), PHI (14-27), PHI (20-27), PHM (1-15) and PHM (13-27), by the solution or solid-phase method for peptide synthesis. Using the highly purified synthetic peptides as immunogens or haptenic immunogens, five kinds of PHI/PHM specific antisera were produced. The major antibody-recognition sites of the five antisera were located respectively in the PHI C-terminal (R8201), in the PHI N-terminal (R8403), in the PHM C-terminal (R8502), and in the PHM whole molecule (R8702 and R8703). Radioimmunoassays (RIAs) with antisera R8201, R8403 and R8502, respectively, showed a wide distribution of immunoreactive (IR) PHI/PHM in porcine and human gastrointestinal and brain tissues. The concentrations of IR-PHI in the porcine gastrointestinal tissues, however, differed between the R8201 and R8403 RIAs employed for measurement. By using these two different PHI RIAs, the IR-PHI in the porcine brain tissue extract was shown to be almost a single component coeluting with synthetic PHI in gel filtration. The IR-PHI in the extract of porcine lower intestine on the other hand, contained, besides a PHI-like component, unidentified component(s) eluting immediately after synthetic PHI in gel filtration; this crossreacted with the PHI C-terminal specific R8201 antiserum but not with the N-terminal specific R8403 antiserum, suggesting the presence of the C-terminal-related fragment(s) of PHI in the tissues.
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D004064:Digestive System / Q000032:analysis; D005768:Gastrointestinal Hormones / Q000032:analysis*; D006801:Humans; D007028:Hypothalamic Hormones / Q000032:analysis*; D007106:Immune Sera; D007202:Indicators and Reagents; D010446:Peptide Fragments / Q000138:chemical synthesis*; D010451:Peptide PHI; D010455:Peptides / Q000032:analysis*; D011498:Protein Precursors / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods; D013552:Swine; D014018:Tissue Distribution; D014660:Vasoactive Intestinal Peptide / Q000032:analysis*
chemical_list: D005768:Gastrointestinal Hormones; D007028:Hypothalamic Hormones; D007106:Immune Sera; D007202:Indicators and Reagents; D010446:Peptide Fragments; D010451:Peptide PHI; D010455:Peptides; D011498:Protein Precursors; D014660:Vasoactive Intestinal Peptide