Search results for "proteolytic enzymes"
showing 10 items of 57 documents
Effects of yeast proteolytic activity on Oenococcus oeni and malolactic fermentation
2006
International audience; Alcoholic fermentation of synthetic must was performed using either Saccharomyces cerevisiae or a mutant Delta pep4, which is deleted for the proteinase A gene. Fermentation with the mutant Delta pep4 resulted in 61% lower levels of free amino acids, and in 62% lower peptide concentrations at the end of alcoholic fermentation than in the control. Qualitative differences in amino acid composition were observed. Changes observed in amino acids in peptides were mainly quantitative. After alcoholic fermentation each medium was inoculated with Oenococcus oeni. Malolactic fermentation in the medium with the Delta pep4 strain took 10 days longer than the control. This diffe…
Growth-dependent release of carbohydrate metabolism-related and antioxidant enzymes from Staphylococcus aureus strain 6 as determined by proteomic an…
2011
Proteins released into the culture medium by Staphylococcus aureus (S. aureus) strain 6 were determined at the end of the exponential growth phase (4.5 h). Eleven proteins were identified by liquid chromatography coupled with mass spectrometry. Three proteins were predicted to have signal peptides indicating their extracellular localization. The other proteins were presumably located in the cytoplasm of the bacteria. Five out of the 11 proteins were involved in carbo- hydrate metabolism. Other intracellular proteins of S. aureus were not detected in the culture medium. This indicates that the release of these 11 proteins was specific and that unspecific protein release due to damaged or dyi…
Behaviour of the plasma concentration of gelatinases and their tissue inhibitors in subjects with venous leg ulcers.
2015
Venous leg ulcers are common in subjects with chronic venous insufficiency. The increased intraluminal pressure causes alteration of the skin microcirculation, leukocyte activation and release of proteolytic enzymes leading to ulceration. An impaired expression and activity of matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs) might influence extracellular matrix degradation and deposition in chronic venous ulcers with the failure of the healing process. Our aim was to evaluate plasma concentration of gelatinases (MMP-2 and MMP-9) and their inhibitors (TIMP-1 and TIMP-2) in subjects with venous leg ulcers before and after the compression therapy. We enrolled 36 subjects (12 …
An approach to identify new antihypertensive agents using Thermolysin as model: In silico study based on QSARINS and docking
2019
Thermolysin is a bacterial proteolytic enzyme, considered by many authors as a pharmacological and biological model of other mammalian enzymes, with similar structural characteristics, such as angiotensin converting enzyme and neutral endopeptidase. Inhibitors of these enzymes are considered therapeutic targets for common diseases, such as hypertension and heart failure. In this report, a mathematical model of Multiple Linear Regression, for ordinary least squares, and genetic algorithm, for selection of variables, are developed and implemented in QSARINS software, with appropriate parameters for its fitting. The model is extensively validated according to OECD standards, so that its robust…
Rational backbone redesign of a fructosyl peptide oxidase to widen its active site access tunnel
2020
Fructosyl peptide oxidases (FPOXs) are enzymes currently used in enzymatic assays to measure the concentration of glycated hemoglobin and albumin in blood samples, which serve as biomarkers of diabetes. However, since FPOX are unable to work directly on glycated proteins, current enzymatic assays are based on a preliminary proteolytic digestion of the target proteins. Herein, to improve the speed and costs of the enzymatic assays for diabetes testing, we applied a rational design approach to engineer a novel enzyme with a wider access tunnel to the catalytic site, using a combination of Rosetta design and molecular dynamics simulations. Our final design, L3_35A, shows a significantly wider …
The contribution of P. acidilactici, L. plantarum, and L. curvatus starters and L-(+)-lactic acid to the acrylamide content and quality parameters of…
2017
Abstract Lactic acid bacteria (LAB) from spontaneous rye sourdough were isolated, identified, and characterized by their growth, acidification rate, and carbohydrate metabolism. The isolated LAB were used for production of rye sourdough, and the influence of sourdough on mixed rye - wheat bread quality and acrylamide formation was evaluated. In addition, comparative studies by using acidification with L-(+)-lactic acid for mixed rye – wheat bread production were performed. Isolated LAB (P. acidilactici, L. plantarum, L. curvatus) demonstrated versatile carbohydrate metabolism, grown at 30 °C and 37 °C, and acidic tolerance. When the isolated strains were used for rye sourdough production, t…
Action de la chlorhexidine sur l'expression de la virulence de
1999
Abstract Candida albicans is an opportunistic yeast. Its pathogenicity is linked to the susceptibility of the host surface as well as to particular factors of the strain: adhesion, filamentous growth and secretion of proteolytic enzymes. Chlorhexidine digluconate is an antiseptic with fungicidal properties. The action of the antiseptic on the growth of the yeast shows a minimal inhibitory concentration (MIC) at 50 μg·mL−1 and a minimal fungicidal concentration (MFC) at 100 μg·mL−1. The consequences of antiseptic treatment are studied using two indicators of pathogenicity: filamentation and the secretion of acid proteinase. Concerning the morphological indicator, a complete inhibition of fil…
Analysis of Structure-Activity Relationships of the Bowman-Birk Inhibitor of Serine Proteinases
1993
Proteinase inhibitors are a class of the various dietary inhibitors of mutagenesis and carcinogenesis (Hayatsu et al., 1988). Schelp and Pongpaew (1988) have recently hypothesized that protection against cancer may result from an increase of endogenous proteinase inhibitors such as α2-macroglobulin induced by diets that are low in calories and fat. The Bowman-Birk inhibitor (BBI) of serine proteinases, a double-headed polypeptide-inhibitor of trypsin and chymotrypsin, is one of the most potent cancer chemopreventive agents (Yavelow et al., 1983, 1985). Recently, this property has been substantiated in an in vivo investigation using mice (St. Clair et al., 1990) that were exposed to dimethyl…
Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2,
2000
Highly cross-linked network polymers prepared by molecular imprinting catalyzed enantioselectively the hydrolysis of N-tert-butoxycarbonyl phenylalanine-p-nitrophenyl ester (BOCPheONP). The templates were designed to allow incorporation of the key catalytic elements, found in the proteolytic enzyme chymotrypsin, into the polymer active sites. Three model systems were evaluated. These were constructed from a chiral phosphonate analogue of phenylalanine (series A, C) or L-phenylalanine (series B) attached by a labile ester linkage to an imidazole-containing vinyl monomer. Free radical copolymerization of the template with methacrylic acid (MAA) and ethylene glycol dimethacrylate (EDMA) gave a…
Design of biopolymeric matrices entrapping bioprotective lactic acid bacteria to control Listeria monocytogenes growth: Comparison of alginate and al…
2014
In order to design biopolymeric matrices entrapping bioprotective lactic acid bacteria (LAB) to control undesirable microorganisms growth in foods, the performances of alginate and alginate-caseinate (an aqueous two-phase system) matrices entrapping Lactococcus lactis subsp. lactis LAB3 cells were compared. Since efficient matrices should preserve the culturability and the antimicrobial activity of entrapped LAB3 cells for prolonged periods, they were both monitored for 12 days storage at 30 °C. Maximal cell density (∼109 CFU mL−1) was reached after 24 h whatever the matrix type. Then, the LAB3 cells population decreased: 107 and 106 CFU mL−1 were enumerated after 12 days in alginate-casein…