Differential subcellular distribution of neurolysin (EC 3.4.24.16) and thimet oligopeptidase (EC 3.3.24.15) in the rat brain

Immunohistochemistry was used to analyze the rat brain distribution of thimet oligopeptidase and neurolysin. Both enzymes appear ubiquitously distributed within the entire rat brain. However, neuronal perikarya and processes stained for neurolysin, while intense nuclear labeling was only observed for thimet oligopeptidase. These data suggest that neurolysin and thimet oligopeptidase, endopeptidases sharing several functional and structural similarities, are present in distinctive intracellular compartments in neuronal cells. (C) 1999 Elsevier B.V. B.V. All rights reserved.

ENDO-OLIGOPEPTIDASE-A, A PUTATIVE ENKEPHALIN-GENERATING ENZYME, IN THE VERTEBRATE RETINA

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.

Expressão, purificação e estudos estruturais da chaperona molecular Hsp65 de Mycobacterium leprae & caracterização da proteína NUDEL - nuclear distribuition element-like

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)