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Distribution and properties of endo-oligopeptidases A and B in the human neuroendocrine system.
Medeiros, M S; Iazigi, N; Camargo, A C; Oliveira, E B.
Afiliação
  • Medeiros MS; Department of Clinical Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
J Endocrinol ; 135(3): 579-88, 1992 Dec.
Article em En | MEDLINE | ID: mdl-1487709
The thiol activated endo-oligopeptidases A and B were studied in the soluble fraction of human hypothalamus and various endocrine glands. For the identification, characterization and purification of the enzymes, Z-Gly-Pro-NH-Np and bradykinin were used as substrates. Endo-oligopeptidase B showed a molecular mass ranging from 55.5 to 65.5 kDa and isoelectric point from 4.7 to 4.95. Its activity in tissues was highest in the testis, with intermediate levels in the thyroid, neurohypophysis, adenohypophysis and hypothalamus and the lowest activity in the pineal gland. Endo-oligopeptidase A, 467-fold purified by immunoaffinity chromatography, exhibited a molecular mass of 65.5 kDa in the adenohypophysis but 58.5 kDa in other tissues. The isoelectric point ranged from 5.22 to 5.50. High endo-oligopeptidase A activity was observed in the adenohypophysis, testis and hypothalamus with lesser activity in the neurohypophysis and thyroid and the lowest in the pineal gland. Endo-oligopeptidase A cleaved the bonds Phe-Ser of bradykinin, Met-Arg of BAM-12P and Arg-Arg of neurotensin as described for rabbit brain and heart and bovine brain enzymes. This work shows that endo-oligopeptidase A also hydrolysed the bonds Tyr-Gly of LH-releasing hormone, Pro-Phe of angiotensin I and Tyr-Ile of angiotensin II.
Assuntos
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Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Cisteína Endopeptidases / Metaloendopeptidases / Sistemas Neurossecretores Limite: Adolescent / Adult / Humans / Male Idioma: En Revista: J Endocrinol Ano de publicação: 1992 Tipo de documento: Article País de afiliação: Brasil País de publicação: Reino Unido
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Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Cisteína Endopeptidases / Metaloendopeptidases / Sistemas Neurossecretores Limite: Adolescent / Adult / Humans / Male Idioma: En Revista: J Endocrinol Ano de publicação: 1992 Tipo de documento: Article País de afiliação: Brasil País de publicação: Reino Unido