Navegando por Palavras-chave "Matrix metalloproteases"

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    Activity of human kallikrein-related peptidase 6 (KLK6) on substrates containing sequences of basic amino acids. Is it a processing protease?
    (Elsevier Science Bv, 2017) Silva, Roberta N. [UNIFESP]; Oliveira, Lilian C. G. [UNIFESP]; Parise, Carolina B. [UNIFESP]; Oliveira, Juliana R. [UNIFESP]; Severino, Beatrice; Corvino, Angela; di Vaio, Paola; Temussi, Piero A.; Caliendo, Giuseppe; Santagada, Vincenzo; Juliano, Luiz [UNIFESP]; Juliano, Maria A. [UNIFESP]
    Human kallikrein 6 (KLK6) is highly expressed in the central nervous system and with elevated level in demyelinating disease. KLK6 has a very restricted specificity for arginine (R) and hydrolyses myelin basic protein, protein activator receptors and human ionotropic glutamate receptor subunits. Here we report a previously unreported activity of KLK6 on peptides containing clusters of basic amino acids, as in synthetic fluorogenic peptidyl-Arg-7-amino-4-carbamoylmethylcoumarin (peptidyl-ACC) peptides and FRET peptides in the format of Abz-peptidyl-Q-EDDnp (where Abz = ortho-aminobenzoic acid and Q-EDDnp = glutaminyl-N-(2,4dinitrophenyl) ethylenediamine), in which pairs or sequences of basic amino acids (R or K) were introduced. Surprisingly, KLK6 hydrolyzed the fluorogenic peptides Bz-A-R down arrow R-ACC and Z-R down arrow R-MCA between the two R groups, resulting in non-fluorescent products. FRET peptides containing furin processing sequences of human MMP-14, nerve growth factor (NGF), Neurotrophin-3 (NT-3) and Neurotrophin-4 (NT-4) were cleaved by KLK6 at the same position expected by furin. Finally, KLK6 cleaved FRET peptides derived from human proenkephalin after the KR, the more frequent basic residues flanking enkephalins in human proenkephalin sequence. This result suggests the ability of KLK6 to release enkephalin from proenkephalin precursors and resembles furin a canonical processing proteolytic enzyme. Molecular models of peptides were built into the KLK6 structure and the marked preference of the cut between the two R of the examined peptides was related to the extended conformation of the substrates. (C) 2017 Elsevier B.V. All rights reserved.
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    Co-distribution of cysteine cathepsins and matrix metalloproteases in human dentin
    (Pergamon-Elsevier Science Ltd, 2017) Scaffa, Polliana Mendes Candia; Breschi, Lorenzo; Mazzoni, Annalisa; Vidal, Cristina de Mattos Pimenta; Curci, Rosa; Apolonio, Fabianni; Gobbi, Pietro; Pashley, David; Tjaderhane, Leo; Tersariol, Ivarne Luis dos Santos [UNIFESP]; Nascimento, Fabio Dupart; Carrilhon, Marcela Rocha; Universidade Federal de São Paulo (UNIFESP)
    It has been hypothesized that cysteine cathepsins (CTs) along with matrix metalloproteases (MMPs) may work in conjunction in the proteolysis of mature dentin matrix. The aim of this study was to verify simultaneously the distribution and presence of cathepsins B (CT-B) and K (CT-K) in partially demineralized dentin; and further to evaluate the activity of CTs and MMPs in the same tissue. The distribution of CT-B and CT-K in sound human dentin was assessed by immunohistochemistry. A double-immunolabeling technique was used to identify, at once, the occurrence of those enzymes in dentin. Activities of CTs and MMPs in dentin extracts were evaluated spectrofluorometrically. In addition, in situ gelatinolytic activity of dentin was assayed by zymography. The results revealed the distribution of CT-B and CT-K along the dentin organic matrix and also indicated co-occurrence of MMPs and CTs in that tissue. The enzyme kinetics studies showed proteolytic activity in dentin extracts for both classes of proteases. Furthermore, it was observed that, at least for sound human dentin matrices, the activity of MMPs seems to be predominant over the CTs one.