Search results for " enzyme"
showing 10 items of 791 documents
Stevia rebaudiana Bertoni as a natural antioxidant/antimicrobial for high pressure processed fruit extract: Processing parameter optimization
2013
Response surface methodology was used to evaluate the optimal high pressure processing treatment (300-500 MPa, 5-15 min) combined with Stevia rebaudiana (Stevia) addition (0-2.5% (w/v)) to guarantee food safety while maintaining maximum retention of nutritional properties. A fruit extract matrix was selected and Listeria monocytogenes inactivation was followed from the food safety point of view while polyphenoloxidase (PPO) and peroxidase (POD) activities, total phenolic content (TPC) and antioxidant capacity (TEAC and ORAC) were studied from the food quality point of view. A combination of treatments achieved higher levels of inactivation of L. monocytogenes and of the oxidative enzymes, s…
Effect of antibodies against cytochrome P-450 on demethylation and denitrosation of N-nitrosodimethylamine and N-nitrosomethylaniline.
1988
Rat liver microsomes which were induced either with ethanol or PB were incubated with NDMA or NMA. Formaldehyde generation and nitrite formation were measured as metabolic parameters for oxidative bioactivation and denitrosation, respectively. The influence of antiserum PB3a1 and PB22 containing antibodies against the corresponding cytochrome P-450 species on both metabolic functions was investigated. The results showed that the influence on formaldehyde production and denitrosation varied independently in that both parameters were either not affected, or influenced in an opposite way, or inhibited to a different degree. Especially remarkable was the 80% inhibition of formaldehyde generatio…
Focus on the unique mechanisms involved in thoracic aortic aneurysm formation in bicuspid aortic valve versus tricuspid aortic valve patients: clinic…
2013
OBJECTIVES: The involvement of different factors in the onset of thoracic aortic aneurysm (TAA) in patients with a bicuspid aortic valve (BAV) vs those with a tricuspid aortic valve (TAV) is well recognized. However, the molecular, genetic and cellular mechanisms driving TAA remain unclear. The aim of this study was to identify the different mechanisms involved in TAA development in patients with BAV vs TAV. METHODS: Aorta specimens and DNA samples were collected from 24 BAV (18 men and 6 women; mean age: 54.2 ± 14.39 years) and 110 TAV (79 men and 31 women, mean age: 66 ± 9.8 years) patients. A control group of 128 subjects (61 men and 67 woman, mean age: 61.1 ± 5.8 years) was also enrolle…
Haptoglobin interacts with apolipoprotein E and beta-amyloid and influences their crosstalk.
2014
Beta-amyloid accumulation in brain is a driving force for Alzheimer's disease pathogenesis. Apolipoprotein E (ApoE) represents a critical player in beta-amyloid homeostasis, but its role in disease progression is controversial. We previously reported that the acute-phase protein haptoglobin binds ApoE and impairs its function in cholesterol homeostasis. The major aims of this study were to characterize the binding of haptoglobin to beta-amyloid, and to evaluate whether haptoglobin affects ApoE binding to beta-amyloid. Haptoglobin is here reported to form a complex with beta-amyloid as shown by immunoblotting experiments with purified proteins, or by its immunoprecipitation in brain tissues …
The biomaterial polyphosphate blocks stoichiometric binding of the SARS-CoV-2 S-protein to the cellular ACE2 receptor
2020
The effect of the polyanionic polymer of inorganic polyphosphate (polyP) involved in innate immunity on the binding of the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein to the cellular ACE2 receptor was studied. The RBD surface comprises a basic amino acid stretch of four arginine residues which interact with the physiological polyP (polyP40) and polyP3. Subsequently, the interaction of RBD with ACE2 is sensitively inhibited. After the chemical modification of arginine, an increased inhibition by polyP, at a 1 : 1 molar ratio (polyP : RBP), is measured already at 0.1 μg mL−1. Heparin was ineffective. The results suggest a potential therapeutic benefit of polyP against SARS-C…
Senataxin defective in ataxia oculomotor apraxia type 2 is involved in the defence against oxidative DNA damage
2007
Adefective response to DNA damage is observed in several human autosomal recessive ataxias with oculomotor apraxia, including ataxia-telangiectasia. We report that senataxin, defective in ataxia oculomotor apraxia (AOA) type 2, is a nuclear protein involved in the DNA damage response. AOA2 cells are sensitive to H2O2, camptothecin, and mitomycin C, but not to ionizing radiation, and sensitivity was rescued with full-length SETX cDNA. AOA2 cells exhibited constitutive oxidative DNA damage and enhanced chromosomal instability in response to H2O2. Rejoining of H2O2-induced DNA double-strand breaks (DSBs) was significantly reduced in AOA2 cells compared to controls, and there was no evidence fo…
Is diet partly responsible for differences in COVID-19 death rates between and within countries?
2020
Abstract Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely use…
Obesity and Outcomes in COVID-19: When an Epidemic and Pandemic Collide.
2020
Obesity has reached epidemic proportions in the United States and in much of the westernized world, contributing to considerable morbidity. Several of these obesity-related morbidities are associated with greater risk for death with coronavirus disease 2019 (COVID-19). Severe acute respiratory syndrome coronavirus 2 penetrates human cells through direct binding with angiotensin-converting enzyme 2 receptors on the cell surface. Angiotensin-converting enzyme 2 expression in adipose tissue is higher than that in lung tissue, which means that adipose tissue may be vulnerable to COVID-19 infection. Obese patients also have worse outcomes with COVID-19 infection, including respiratory failure, n…
In vitro evaluation of bacteriocinlike inhibitory substances produced by lactic acid bacteria isolated during traditional sicilian cheese making
2016
Bacteriocins are antimicrobial proteins produced by bacteria that inhibit with a bactericidal or bacteriostatic mode of action, the growth of other bacteria. Many lactic acid bacteria (LAB) produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognized as safe (GRAS) and useful to control the frequent development of pathogens and spoilage microorganisms; for this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances (BLIS), by …
Usefulness of omp1 restriction mapping for avian Chlamydia psittaci isolate differentiation
1995
Abstract Sixty-five avian Chlamydia psittaci isolates collected worldwide, including 27 previously characterized reference strains, were analysed by restriction mapping of the major outer membrane protein gene ( omp1 ) obtained after DMA amplification by PCR. They were compared to 2 ruminant isolates, a feline pneumonitis and a guinea pig inclusion conjunctivitis (GPIC) isolate. According to their omp1 restriction patterns, avian strains were heterogeneous in that they exhibited 6 and 4 distinct patterns using Alu I and Mbo II restriction enzymes, respectively, thus defining 7 groups. However, 84% of the studied strains belonged to groups 1 to 4, which share a specific fragment triplet of 4…