Search results for "proteolytic enzymes"
showing 10 items of 57 documents
In Vitro Bioactivity of Astaxanthin and Peptides from Hydrolisates of Shrimp (Parapenaeus longirostris) By-Products: From the Extraction Process to B…
2021
Non-edible parts of crustaceans could be a rich source of valuable bioactive compounds such as the carotenoid astaxanthin and peptides, which have well-recognized beneficial effects. These compounds are widely used in nutraceuticals and pharmaceuticals, and their market is rapidly growing, suggesting the need to find alternative sources. The aim of this work was to set up a pilot-scale protocol for the reutilization of by-products of processed shrimp, in order to address the utilization of this valuable biomass for nutraceutical and pharmaceuticals application, through the extraction of astaxanthin-enriched oil and antioxidant-rich protein hydrolysates. Astaxanthin (AST) was obtained using …
Naturally occurring hemolysins in the coelomic fluid of Holothuria polii delle chiaie (Echinodermata).
1979
Abstract The coelomic fluid of Holothuria polii D.Ch contains hemolytic activity against erythrocytes of several vertebrate species. The hemolytic potency depends upon calcium ion concentration and varies according to erythrocyte source and cell number in the reaction mixture. Absorption experiments with formalinized rabbit erythrocytes suggest that hemolytic activity is not specific. Its heat lability, water insolubility at low pH values, and sensitivity to proteolytic enzymes suggest that hemolytic activity resides in protein molecules. The activity, maximal in alkaline media, appears to depend up time and temperature.
Cigarette smoke exposure inhibits extracellular MMP-2 (gelatinase A) activity in human lung fibroblasts
2007
Abstract Background Exposure to cigarette smoke is considered a major risk factor for the development of lung diseases, since its causative role has been assessed in the induction and maintenance of an inflamed state in the airways. Lung fibroblasts can contribute to these processes, due to their ability to produce proinflammatory chemotactic molecules and extracellular matrix remodelling proteinases. Among proteolytic enzymes, gelatinases A and B have been studied for their role in tissue breakdown and mobilisation of matrix-derived signalling molecules. Multiple reports linked gelatinase deregulation and overexpression to the development of inflammatory chronic lung diseases such as COPD.…
Enzymatic Activity of CD26 (Dipeptidylpeptidase IV) is not Required for Its Signalling Function in T Cells
1993
Abstract CD26 is a proteolytic enzyme (dipeptidylpeptidase IV) expressed on the T cell surface that defines an alternative activation signal for human T lymphocytes. Crosslinking of CD26 via monoclonal antibodies triggers proliferation and cytotoxicity in preactivated T cells. In this study, we used highly specific competitive and irreversible inhibitors of dipeptidylpeptidase IV to study the role of the enzymatic activity in activation of CD26- transfected T cells as well as of CD26-expressing normal human T cell clones. These inhibitors at concentrations that blocked up to 95% of the enzymatic activity, did not specifically inhibit T cell activation neither via TCR/CD3 nor via CD26 itself…
Data concerning the proteolytic resistance and oxidative stress in LAN5 cells after treatment with BSA hydrogels
2016
AbstractProteolytic resistance is a relevant aspect to be tested in the formulation of new nanoscale biomaterials. The action of proteolytic enzymes is a very fast process occurring in the range of few minutes. Here, we report data concerning the proteolytic resistance of a heat-set BSA hydrogel obtained after 20-hour incubation at 60°C prepared at the pH value of 3.9, pH at which the hydrogel presents the highest elastic character with respect to gel formed at pH 5.9 and 7.4 “Heat-and pH-induced BSA conformational changes, hydrogel formation and application as 3D cell scaffold” (G. Navarra, C. Peres, M. Contardi, P. Picone, P.L. San Biagio, M. Di Carlo, D. Giacomazza, V. Militello, 2016) […
Purification and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds.
2013
Aminopeptidases (EC 3.4.11) are proteolytic enzymes, which hydrolyze one amino acid from N-terminus of peptidic substrates. Inhibitors of plant aminopeptidases can find an application in agriculture as herbicides. Isolation and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds has been described. The enzyme was purified to molecular homogeneity using a six-step purification procedure (precipitation with (NH4)2SO4, followed by chromatography on Sephadex G-25, DEAE-Sepharose, Sephacryl HR 300, Macro-Prep Q and Phenyl-Sepharose HP columns). The enzyme was purified 365-fold with recovery above 18%. The molecular weight of the purified enzyme was determined by SDS…
The mechanism of formamide hydrolysis in water from ab initio calculations and simulations.
2005
The neutral hydrolysis of formamide in water is a suitable reference to quantify the efficiency of proteolytic enzymes. However, experimental data for this reaction has only very recently been obtained and the kinetic constant determined experimentally is significantly higher than that predicted by previous theoretical estimations. In this work, we have investigated in detail the possible mechanisms of this reaction. Several solvent models have been considered that represent a considerable improvement on those used in previous studies. Density functional and ab initio calculations have been carried out on a system which explicitly includes the first solvation shell of the formamide molecule…
Hereditary angioneurotic oedema and blood-coagulation: interaction between C1-esterase-inhibitor and the activation factors of the proteolytic enzyme…
1983
C-1-inactivator (C-1-INA) does not only exert its important inhibitory functions in the complement system but also in the first step in the activation of the coagulation, fibrinolytic and kallikrein system. We therefore determined in nine patients with hereditary angioneurotic oedema (HANE) with obvious quantitative or functional defects of C-1-INA, and one further patient with Quincke-type oedema of different origin, the coagulation factors of the initial phase such as Hageman factor, plasma thromboplastin antecedent (PTA) and high molecular weight kininogen (HMWK). These factors were further correlated with the concentration as well as functional activity of C-1-INA. Nine of ten patients …
Proteolytic Enzymes Clustered in Specialized Plasma-Membrane Domains Drive Endothelial Cells’ Migration
2016
In vitro cultured endothelial cells forming a continuous monolayer establish stable cell-cell contacts and acquire a "resting" phenotype; on the other hand, when growing in sparse conditions these cells acquire a migratory phenotype and invade the empty area of the culture. Culturing cells in different conditions, we compared expression and clustering of proteolytic enzymes in cells having migratory versus stationary behavior. In order to observe resting and migrating cells in the same microscopic field, a continuous cell monolayer was wounded. Increased expression of proteolytic enzymes was evident in cell membranes of migrating cells especially at sprouting sites and in shed membrane vesi…
Morpholino knockdown of the ubiquitously expressed transmembrane serine protease TMPRSS4a in zebrafish embryos exhibits severe defects in organogenes…
2011
AbstractOver the past years the members of the type II transmembrane serine protease (TTSP) family have emerged as new players in mammalian biology. TMPRSS4 (transmembraneprotease/serine) is overexpressed in several human cancer tissues, promoting invasion, migration, and metastasis. However, the physiological function has not yet been elucidated. Here, we present morpholino knockdown studies targeting TMPRSS4a, a homolog of human TMPRSS4 in zebrafish embryos. By RT-PCR, we could demonstrate an expression of this protease already 5 h post-fertilization, suggesting important functions in the early stages of embryonic development. Indeed,in vivogene silencing caused severe defects in tissue d…