title: Presence of endo-oligopeptidase (EC 3.4.22.19), a putative neuropeptide-metabolizing endopeptidase in cells of the immune system.
abstract: Neuropeptides have been shown to modulate the bidirectional communication between the central nervous and immune systems. The endooligopeptidase (EC 3.4.22.19), originally isolated and characterized in the nervous tissue, was shown to hydrolyse several neuropeptides and to generate enkephalin from enkephalin-containing peptides. This report shows the presence of endopeptidase 22.19 in the rat immune system using both biochemical and immunochemical methods. The specific activity of endopeptidase 22.19 in soluble fraction of lymphocytes was 3-4-fold higher than the one found in the nervous tissue. Among rat blood cells the highest specific activity of endopeptidase 22.19 was found in T lymphocytes, being 2.5-fold higher than the activity found in other leukocytes. Immunocytochemical studies performed in tissues and cells of the immune system indicate the presence of endopeptidase 22.19-like enzyme in all types of leukocytes. The occurrence of this enzyme in cells of the immune system can be considered an important step in understanding the metabolism of neuropeptides in the immune system as well as its possible participation as a regulatory enzyme in neuroimmunomodulation.
authors.affiliation: Department of Pharmacology, University of São Paulo, Brazil.
authors.forename: S H
authors.initials: SH
authors.lastname: Paik
authors.forename: F
authors.initials: F
authors.lastname: Betti
authors.forename: A C
authors.initials: AC
authors.lastname: Camargo
authors.forename: E S
authors.initials: ES
authors.lastname: de Oliveira
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000201:enzymology; D015153:Blotting, Western; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D007107:Immune System / Q000166:cytology / Q000201:enzymology*; D007150:Immunohistochemistry; D008099:Liver; D008214:Lymphocytes / Q000201:enzymology; D008221:Lymphoid Tissue / Q000166:cytology / Q000201:enzymology; D008666:Metalloendopeptidases; D009479:Neuropeptides / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D009479:Neuropeptides; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D008666:Metalloendopeptidases; C022510:thimet oligopeptidase