Navegando por Palavras-chave "Proteinases"

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    Proteinase activity regulation by glycosaminoglycans
    (Associação Brasileira de Divulgação Científica, 2002-02-01) Tersariol, Ivarne Luis dos Santos [UNIFESP]; Pimenta, D.c. [UNIFESP]; Chagas, Jair Ribeiro [UNIFESP]; Almeida, P.c.; Universidade de Mogi das Cruzes Centro Interdisciplinar de Investigação Bioquímica; Universidade Federal de São Paulo (UNIFESP)
    There are few reports concerning the biological role and the mechanisms of interaction between proteinases and carbohydrates other than those involved in clotting. It has been shown that the interplay of enzymes and glycosaminoglycans is able to modulate the activity of different proteases and also to affect their structures. From the large number of proteases belonging to the well-known protease families and also the variety of carbohydrates described as widely distributed, only few events have been analyzed more deeply. The term family is used to describe a group of proteases in which every member shows an evolutionary relationship to at least one other protease. This relationship may be evident throughout the entire sequence, or at least in that part of the sequence responsible for catalytic activity. The majority of proteases belong to the serine, cysteine, aspartic or metalloprotease families. By considering the existing limited proteolysis process, in addition to the initial idea that the proteinases participate only in digestive processes, it is possible to conclude that the function of the enzymes is strictly limited to the cleavage of intended substrates since the destruction of functional proteins would result in normal tissue damage. In addition, the location as well as the eventual regulation of protease activity promoted by glycosaminoglycans can play an essential role in the development of several physiopathological conditions.
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    Purification and biochemical characterization of an extracellular serine peptidase from aspergillus terreus
    (Taylor & francis inc, 2016) Biaggio, Rafael Tage; da Silva, Ronivaldo Rodrigues; da Rosa, Nathalia Gonsales; Ribeiro Leite, Rodrigo Simoes; Arantes, Eliane Candiani; de Freitas Cabral, Tatiana Pereira; Juliano, Maria A. [UNIFESP]; Juliano, Luiz [UNIFESP]; Cabral, Hamilton
    Peptidases are important because they play a central role in pharmaceutical, food, environmental, and other industrial processes. A serine peptidase from Aspergillus terreus was isolated after two chromatography steps that showed a yield of 15.5%. Its molecular mass was determined to be 43 kD, by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). This peptidase was active between pH 5.0 to 8.0 and had maximum activity at pH 7.0, at 45 degrees C. When exposited with 1 M of urea, the enzyme maintained 100% activity and used azocasein as substrate. The N-terminal (first 15 residues) showed 33% identity with the serine peptidase of Aspergillus clavatus ES1. The kinetics assays showed that subsite S-2 did not bind polar basic amino acids (His and Arg) nonpolar acidic amino acids (Asp and Glu). The subsite S-1 showed higher catalytic efficiency than the S-2 and S-3 subsites.