ENDO-OLIGOPEPTIDASE-A, A PUTATIVE ENKEPHALIN-GENERATING ENZYME, in the VERTEBRATE RETINA

ENDO-OLIGOPEPTIDASE-A, A PUTATIVE ENKEPHALIN-GENERATING ENZYME, in the VERTEBRATE RETINA

Author Ferro, E. S. Google Scholar
Hamassaki, D. E. Google Scholar
Camargo, ACM Google Scholar
Britto, LRG Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
São Paulo STATE UNIV
Abstract Endo-oligopeptidase A, EC 3.4.22.19, converts small enkephalin-containing peptides into the corresponding enkephalins in vitro. We investigated the presence of endooligopeptidase A in the retina and its possible colocalization with enkephalins in retinal neurons. the specific activity of endo-oligopeptidase A found in pigeon retinae (30.3 +/- 7.3 mU/mg, mean +/- standard deviation) was four times higher than in rabbit retinae (7.0 +/- 1.1 mU/mg). the enzyme activity was not modified by EDTA, but it was enhanced by dithiothreitol and inhibited by zinc and 5,5'-dithiobis(2-nitrobenzoic acid). Immunohistochemical experiments with a purified antiserum against rabbit endo-oligopeptidase A revealed labeled neurons in both the inner nuclear layer and the ganglion cell layer of pigeon and rabbit retinae. Double-labeling immunofluorescence experiments demonstrated that about 90% of neurons containing endo-oligopeptidase A-like immunoreactivity also contained [Leu5]-enkephalin-like immunoreactivity. These colocalization results may represent an important step toward the demonstration of the possible involvement of endo-oligopeptidase A in enkephalin generation in vivo.
Keywords ENDO-OLIGOPEPTIDASE-A
ENDOPEPTIDASE 22.19
ENKEPHALINS
OPIOID PEPTIDES
RETINAL NEUROPEPTIDES
Language English
Date 1991-11-01
Published in Journal of Neurochemistry. Philadelphia: Lippincott-raven Publ, v. 57, n. 5, p. 1643-1649, 1991.
ISSN 0022-3042 (Sherpa/Romeo, impact factor)
Publisher Lippincott-raven Publ
Extent 1643-1649
Origin http://dx.doi.org/10.1111/j.1471-4159.1991.tb06363.x
Access rights Closed access
Type Article
Web of Science ID WOS:A1991GL28800025
URI http://repositorio.unifesp.br/handle/11600/25228

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