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| Puccia,R.; Juliano,M.A.; Juliano,L.; Travassos,L.R.; Carmona,A.K.. |
| We have characterized, in the Paracoccidioides brasiliensis yeast phase, an exocellular SH-dependent serine proteinase activity against Abz-MKRLTL-EDDnp and analogous fluorescent-quenched peptides, and showed that it is also active against constituents of the basement membrane in vitro. In the present study, we separated the components of P. brasiliensis culture filtrates by electrophoresis and demonstrated that the serine-thiol exocellular proteinase has a diffuse and heterogeneous migration by SDS-PAGE, localizing in a region between 69 and 43 kDa. The hydrolytic activity was demonstrable after SDS-PAGE using buffered agarose overlays of Abz-MKALTLQ-EDDnp, following incubation at 37oC, and detection of fluorescent bands with a UV transilluminator.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: P. brasiliensis; Serine-thiol proteinase; SDS-PAGE; Fluorescent-quenched peptides. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000500019 |
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| Anéas,M.A.F.; Portaro,F.C.V.; Lebrun,I.; Juliano,L.; Palma,M.S.; Fernandes,B.L.. |
| The opportunistic bacterium Proteus mirabilis secretes a metalloprotease, ZapA, considered to be one of its virulence factors due to its IgA-degrading activity. However, the substrate specificity of this enzyme has not yet been fully characterized. In the present study we used fluorescent peptides derived from bioactive peptides and the oxidized ß-chain of insulin to determine the enzyme specificity. The bradykinin- and dynorphin-derived peptides were cleaved at the single bonds Phe-Ser and Phe-Leu, with catalytic efficiencies of 291 and 13 mM/s, respectively. Besides confirming already published cleavage sites, a novel cleavage site was determined for the ß-chain of insulin (Val-Asn). Both the natural and the recombinant enzyme displayed the same broad... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Proteus mirabilis; Metalloprotease; Substrate specificity; Fluorogenic peptides; IgA; Insulin ß-chain. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001100004 |
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| Alves,M.F.; Araujo,M.C.; Juliano,M.A.; Oliveira,E.M.; Krieger,J.E.; Casarini,D.E.; Juliano,L.; Carmona,A.K.. |
| A continuous assay using internally quenched fluorescent peptides with the general sequence Abz-peptidyl-(Dnp)P-OH (Abz = ortho-aminobenzoic acid; Dnp = 2,4-dinitrophenyl) was optimized for the measurement of angiotensin I-converting enzyme (ACE) in human plasma and rat tissues. Abz-FRK(Dnp)P-OH, which was cleaved at the Arg-Lys bond by ACE, was used for the enzyme evaluation in human plasma. Enzymatic activity was monitored by continuous recording of the fluorescence (lambdaex = 320 nm and lambdaem = 420 nm) at 37ºC, in 0.1 M Tris-HCl buffer, pH 7.0, with 50 mM NaCl and 10 µM ZnCl2. The assays can be performed directly in the cuvette of the fluorimeter and the hydrolysis followed for 5 to 10 min. ACE measurements in the plasma of 80 healthy patients with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Angiotensin-converting enzyme activity; Fluorometric assay; Rat tissue angiotensin- converting enzyme; Human plasma angiotensin-converting enzyme. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000600007 |
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| Fernandes,B.L.; Anéas,M.A.F.; Juliano,L.; Palma,M.S.; Lebrun,I.; Portaro,F.C.V.. |
| The protease ZapA, secreted by Proteus mirabilis, has been considered to be a virulence factor of this opportunistic bacterium. The control of its expression requires the use of an appropriate methodology, which until now has not been developed. The present study focused on the replacement of azocasein with fluorogenic substrates, and on the definition of enzyme specificity. Eight fluorogenic substrates were tested, and the peptide Abz-Ala-Phe-Arg-Ser-Ala-Ala-Gln-EDDnp was found to be the most convenient for use as an operational substrate for ZapA. A single peptide bond (Arg-Ser) was cleaved with a Km of 4.6 µM, a k cat of 1.73 s-1, and a catalytic efficiency of 376 (mM s)-1. Another good substrate for ZapA was peptide 6... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Metalloprotease; Substrate specificity; Quenched fluorescence peptides; Proteus mirabilis. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000700006 |
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| Medeiros,M.A.S.; França,M.S.F.; Boileau,G.; Juliano,L.; Carvalho,K.M.. |
| Two intramolecularly quenched fluorogenic peptides containing o-aminobenzoyl (Abz) and ethylenediamine 2,4-dinitrophenyl (EDDnp) groups at amino- and carboxyl-terminal amino acid residues, Abz-<!-- $MVD$:face("Times") -->DArg-Arg-Leu-EDDnp (Abz-<!-- $MVD$:face("Times") -->DRRL-EDDnp) and Abz-<!-- $MVD$:face("Times") -->DArg-Arg-Phe-EDDnp (Abz-<!-- $MVD$:face("Times") -->DRRF-EDDnp), were selectively hydrolyzed by neutral endopeptidase (NEP, enkephalinase, neprilysin, EC 3.4.24.11) at the Arg-Leu and Arg-Phe bonds, respectively. The kinetic parameters for the NEP-catalyzed hydrolysis of Abz-<!-- $MVD$:face("Times") -->DRRL-EDDnp and Abz-<!-- $MVD$:face("Times") -->DRRF-EDDnp were Km = 2.8 µM, kcat = 5.3 min-1, kcat/Km = 2... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Neutral endopeptidase; Enkephalinase; Neprilysin; Fluorogenic substrates; Phosphoramidon. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001000003 |
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| Lotfi,C.F.P.; Lepique,A.P.; Forti,F.L.; Schwindt,T.T.; Eichler,C.B.; Santos,M.O.; Rebustini,I.T.; Hajj,G.N.M.; Juliano,L.; Armelin,H.A.. |
| This article reviews recent results of studies aiming to elucidate modes of integrating signals initiated in ACTH receptors and FGF2 receptors, within the network system of signal transduction found in Y1 adrenocortical cells. These modes of signal integration should be central to the mechanisms underlying the regulation of the G0->G1->S transition in the adrenal cell cycle. FGF2 elicits a strong mitogenic response in G0/G1-arrested Y1 adrenocortical cells, that includes a) rapid and transient activation of extracellular signal-regulated kinases-mitogen-activated protein kinases (ERK-MAPK) (2 to 10 min), b) transcription activation of c-fos, c-jun and c-myc genes (10 to 30 min), c) induction of c-Fos and c-Myc proteins by 1 h and cyclin D1 protein by... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: ACTH; FGF2; Signal transduction; MAP kinases; Early response genes. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001000002 |
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| Carvalho,K.M.; Nava,R.A.; França,M.S.F.; Medeiros,M.A.S.; Camarão,G.C.; Juliano,L.. |
| A new metalloendopeptidase was purified to apparent homogeneity from a homogenate of normal human liver using successive steps of chromatography on DEAE-cellulose, hydroxyapatite and Sephacryl S-200. The purified enzyme hydrolyzed the Pro7-Phe8 bond of bradykinin and the Ser25-Tyr26 bond of atrial natriuretic peptide. No cleavage was produced in other peptide hormones such as vasopressin, oxytocin or Met- and Leu-enkephalin. This enzyme activity was inhibited by 1 mM divalent cation chelators such as EDTA, EGTA and o-phenanthroline and was insensitive to 1 µM phosphoramidon and captopril, specific inhibitors of neutral endopeptidase (EC 3.4.24.11) and angiotensin-converting enzyme (EC 3.4.15.1), respectively. With Mr 85 kDa, the enzyme exhibits optimal... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Liver metalloendopeptidase; Bradykinin; Atrial natriuretic peptide. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000100007 |
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