Produção Nacional
Revisado por pares
Endo‐Oligopeptidase A., a Putative Enkephalin‐Generating Enzyme, in the Vertebrate Retina
1991; Wiley; Volume: 57; Issue: 5 Linguagem: Inglês
10.1111/j.1471-4159.1991.tb06363.x
ISSN1471-4159
AutoresEmer S. Ferro, Dânia Emi Hamassaki‐Britto, Antônio Carlos Martins de Camargo, Luiz R.G. Britto,
Tópico(s)Biochemical and Structural Characterization
ResumoAbstract : 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 immune‐reactivity also contained [Leu 5 )‐enkephalin‐like immuno‐reactivity. These colocalization results may represent an important step toward the demonstration of the possible involvement of endo‐oligopeptidase A in enkephalin generation in vivo.
Referência(s)