activity of enzymes
Recently Published Documents


TOTAL DOCUMENTS

661
(FIVE YEARS 183)

H-INDEX

47
(FIVE YEARS 5)

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 500
Author(s):  
Martyna N. Wieczorek ◽  
Piotr Mariusz Pieczywek ◽  
Justyna Cybulska ◽  
Artur Zdunek ◽  
Henryk H. Jeleń

The storage of plant samples as well as sample preparation for extraction have a significant impact on the profile of metabolites, however, these factors are often overlooked during experiments on vegetables or fruit. It was hypothesized that parameters such as sample storage (freezing) and sample pre-treatment methods, including the comminution technique or applied enzyme inhibition methods, could significantly influence the extracted volatile metabolome. Significant changes were observed in the volatile profile of broccoli florets frozen in liquid nitrogen at −20 °C. Those differences were mostly related to the concentration of nitriles and aldehydes. Confocal microscopy indicated some tissue deterioration in the case of slow freezing (−20 °C), whereas the structure of tissue, frozen in liquid nitrogen, was practically intact. Myrosinase activity assay proved that the enzyme remains active after freezing. No pH deviation was noted after sample storage - this parameter did not influence the activity of enzymes. Tissue fragmentation and enzyme-inhibition techniques applied prior to the extraction influenced both the qualitative and quantitative composition of the volatile metabolome of broccoli.


2022 ◽  
Vol 23 (2) ◽  
pp. 748
Author(s):  
Damian Jozef Flis ◽  
Emilia Gabriela Bialobrodzka ◽  
Ewa Aleksandra Rodziewicz-Flis ◽  
Zbigniew Jost ◽  
Andzelika Borkowska ◽  
...  

This study investigates the effect of Dexamethasone (Dex) treatment on blood and skeletal muscle metabolites level and skeletal muscle activity of enzymes related to energy metabolism after long-duration swimming. To evaluate whether Dex treatment, swimming, and combining these factors act on analyzed data, rats were randomly divided into four groups: saline treatment non-exercise and exercise and Dex treatment non-exercised and exercised. Animals in both exercised groups underwent long-lasting swimming. The concentration of lipids metabolites, glucose, and lactate were measured in skeletal muscles and blood according to standard colorimetric and fluorimetric methods. Also, activities of enzymes related to aerobic and anaerobic metabolism were measured in skeletal muscles. The results indicated that Dex treatment induced body mass loss and increased lipid metabolites in the rats’ blood but did not alter these changes in skeletal muscles. Interestingly, prolonged swimming applied after 9 days of Dex treatment significantly intensified changes induced by Dex; however, there was no difference in skeletal muscle enzymatic activities. This study shows for the first time the cumulative effect of exercise and Dex on selected elements of lipid metabolism, which seems to be essential for the patient’s health due to the common use of glucocorticoids like Dex.


2022 ◽  
pp. 089875642110666
Author(s):  
Natália Goulart Leite ◽  
Thiago Henrique Moroni Vargas ◽  
Daniel Giberne Ferro ◽  
Renata Afonso Sobral ◽  
Michèle Alice Françoise Anita Venturini ◽  
...  

The majority of the melanocytic neoplasms are considered malignant and highly metastatic. However, a subset of the melanocytic tumors has a more favorable prognosis and the identification of precise prognostic markers for this neoplasm may be useful to guide treatment. The collagen architecture and density have been shown to correlate with tumor progression in human breast cancer and canine mast cell tumors. The purpose of the present study was to investigate the prognostic value of the intratumoral collagen index (ICI) as an indicator of postsurgical survival and its relation with other prognostic markers for canine oral melanomas (OMs). Twenty-two cases were tested for intratumoral collagen density using Masson's trichrome stain and morphometry. No differences were found between dogs regarding survival. The ICI was not correlated with proliferative activity or nuclear atypia. The results presented herein indicate that the quantity of intratumoral collagen in canine OMs is not an efficient indicator of postsurgical survival. Complementary studies about the expression and activity of enzymes that are capable of degrading extracellular matrix (ECM) components are necessary.


2021 ◽  
Vol 5 (4) ◽  
Author(s):  
Svetlana Dekina

Background. The catalytic activity of enzymes, which is their most important characteristic, can change significantly under the influence of effectors, for example, metal ions, and is the subject of special studies that are important for biochemistry, biotechnology, medicine, and other branches of science. Usually, the activity of enzymes in the presence of metals is assessed by the change in the rate of the enzymatic reaction. However, conducting similar experimental studies, especially for new enzymes, as in the case of peptidase Bacillus thuringiensis var. israelensis IMV B-7465, requires significant resources and extensive kinetic research. Therefore, it is advisable to use the methods of computer chemistry, the basic task of which is to search for the structure-property relationship, to build a model that can, with a high degree of probability, assess the effect of metal ions on the activity of peptidase. Objective: Objective: to develop of QSAR models to analyze and prediction the effect of metal ions on the activity of peptidase Bacillus thuringiensis var. israelensis IMV B-7465. Methods: the effect of metal ions was studied by determining the proteolytic activity of peptidase after joint incubation for 30 min in 0.0167 M Tris-HCl buffer solution (pH 7.5, 37 ° C). Final concentration of metal chlorides Li +; Na +; K +; Cs +; Cu2 +; Be2 +; Mg2 +; Ca2 +; Sr2 +; Ba2 +; Zn2 +; Cd2 +; Hg2 +; Cr3 +; Mn2 +; Co2 +; Ni2 + in the buffer solution was 4 mmol / dm3. To search for the quantitative “structure-property” relationship we used the reference data on the properties of metal ions and trend vector and random forest methods. Results: the effect of metal ions on the proteolytic activity of peptidase Bacillus thuringiensis var. israelensis IMV B-7465, some metal ions (Li +, Mn2 +, and Co2 +) activated peptidase, while others (Cu2 +, Be2 +, Cd2 +, Hg2 +, Cr3 +) inhibited the enzyme activity. Adequate statistical models without classification errors and prediction errors for the test set were constructed by nonlinear methods of trend-vector and random forest. Both models show that the most important characteristics of metal ions that affect enzyme activity are electronegativity (ENPol), first ionization potential (IP1), the entropy of ions in aqueous solution (S) and the electron affinity energy (Eae). Conclusions: methods of QSAR analysis in combination with nonlinear methods of trend vector and random forest allow to adequately describe the influence of metal ions on the activity of peptidase Bacillus thuringiensis var. israelensis IMV B-7465 due to descriptors that reflect a certain balance of their electron-donor and electron-acceptor properties (electronegativity, first ionization potential, electron affinity energy) and the degree of the hydrate shell structurization (entropy of solvation). Both statistical methods give similar values of the importance of descriptors, but only the trend vector method allows to analyze the direction of influence of specific characteristics of ions.


2021 ◽  
Vol 51 (3) ◽  
pp. 98-100
Author(s):  
V. H. Inoyatova

Thirty females suffering from sterility were examined. Fertility disorders were accompanied by hyperandrogeny. Hormones FSH, LH, testosterone and progesterone in blood were studied. Besides, an activity of enzymes GPO, GTD, GST, G-6-PD in washed erythrocytes and tissue homogenate of ovary was investigated. Findings obtained demonstrate noticeable disorders in glutathione detoxication processes in females with infertility and they are related to hormones level, in particular androgens. An increase of GPO in females with hyperandrogeny showed deepupdates in metabolism processes of steroid hormones in ovary. It manifests beforehand for development of follicle that is predictive sign of unovulation in the beginning of menstrual cycle.


2021 ◽  
Vol 12 ◽  
Author(s):  
Juliana da Silva Fonseca ◽  
Laura Fernandes de Barros Marangoni ◽  
Joseane Aparecida Marques ◽  
Adalto Bianchini

The frequency and severity of coral bleaching events have increased in recent years. Global warming and contamination are primarily responsible for triggering these responses in corals. Thus, the objective of this study was to evaluate the isolated and combined effects of elevated temperature and exposure to copper (Cu) on responses of the antioxidant defense system of coral Mussismilia harttii. In a marine mesocosm, fragments of the coral were exposed to three temperatures (25.0, 26.6, and 27.3°C) and three concentrations of Cu (2.9, 5.4, and 8.6 μg/L) for up to 12 days. Levels of reduced glutathione (GSH) and the activity of enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutamate cysteine ligase (GCL), were evaluated on the corals and symbionts. The short exposure to isolated and combined stressors caused a reduction in GSH levels and inhibition of the activity of antioxidant enzymes. After prolonged exposure, the combination of stressors continued to reduce GSH levels and SOD, CAT, and GCL activity in symbionts and GST activity in host corals. GCL activity was the parameter most affected by stressors, remaining inhibited after 12-days exposure. Interesting that long-term exposure to stressors stimulated antioxidant defense proteins in M. harttii, demonstrating a counteracting response that may beneficiate the oxidative state. These results, combined with other studies already published suggest that the antioxidant system should be further studied in order to understand the mechanisms of tolerance of South Atlantic reefs.


2021 ◽  
Vol 12 ◽  
Author(s):  
Murali Kumar ◽  
Joseph Tierney ◽  
Martin Wilkinson

Bacteria are capable of colonizing industrial processing surfaces creating biofilms on them which may adversely affect the quality and safety of products. Traditional cleaning-in-place (CIP) treatments using caustic and nitric acid solutions have been known to exhibit variable efficiency in eliminating biofilm bacteria. Here, we introduce enzymes as an alternative to traditional CIP treatments and discuss their mechanism of action against bacterial biofilms in cheese manufacturing. In addition, we discuss research gaps namely thermal stability, substrate specificity and residual activity of enzymes that may play a vital role in the selection of enzymes with optimal effectiveness against multi species biofilms. The outcome of this mini review will aid in the development of a novel and sustainable enzyme-based CIP treatment during cheese manufacturing in the future.


2021 ◽  
Author(s):  
Lamia M. El-Samad ◽  
Mohamed S. El-Gerbed ◽  
Hanaa S. Hussein ◽  
Justin Flaven-Pouchon ◽  
Abeer El Wakil ◽  
...  

Abstract Neonicotinoids are modern insecticides widely used in agriculture worldwide. Their impact on target (nervous system) and non-target (midgut) tissues has been well studied in beneficial insects including honeybees. However, their effects on pest insects on the field are comparably rarely described. Here, we have studied the effects of the neonicotinoid imidacloprid on the midgut of the pest insect Locusta migratoria caught in the field. We found that in the midgut of imidacloprid-exposed locusts the activity of enzymes involved in reactive oxygen metabolism was perturbed. By contrast, the activity of P450 enzymes that have been shown to be activated in a detoxification response and that were also reported to produce reactive oxygen species was elevated. Probably as a consequence, markers of oxidative stress including protein carbonylation and lipid peroxidation accumulated in midgut samples of these locusts. Histological analyses revealed that their midgut epithelium is disorganized and that the brush border of the epithelial cells is markedly reduced. Indeed, microvilli are significantly shorter, misshapen and possibly non-functional in imidacloprid-treated locusts. We hypothesize that imidacloprid induces oxidative stress in the locust midgut, thereby changing the shape of midgut epithelial cells and probably in turn compromising their physiological function. Presumably, these effects reduce the survival rate of imidacloprid-treated locusts and the damage they cause in the field.


Author(s):  
E.A. Salashnaya ◽  
◽  
N.P. Zuev ◽  

Modern animal husbandry, including poultry farming, is characterized by the presence of numerous stress factors. The studies carried out have established that under their influence there is a decrease in the content of erythrocytes, as well as in them hemoglobin, a decrease in the content of total protein and calcium. Analyzing the data obtained, it can be concluded that under the influence of new macrolido compounds in the blood of chickens, the content of total protein increased in the structure of protein fractions of albumin and alpha globulins. With regard to other biochemical indicators - a decrease in the content of uric acid and creatinine. In the study of the catalytic activity of enzymes, a decrease in that of AcAt, AlAt and a tendency to an increase in alkaline phosphatase and amylase were found. When conducting a high-quality coagulation test by Veltman, a decrease in the disturbance of the structure of the protein fractions of blood serum was determined.


2021 ◽  
Vol 14 (1) ◽  
pp. 57-83
Author(s):  
Zs. Zurbó ◽  
J. Csapó

Abstract In this paper, we examine the role and effect of resistant starch (RS) in human nutrition; further, the structure and properties of RS, the food sources based on resistance to digestion in the colon, and the physiological effects of RS are described. The nutritional value of RS, the effect of RS on short-chain fatty acid (SCFA) production, the relationships between RS and colon function, and the relationships between food starch, dietary fibre, and RS content and colon cancer development are reviewed. It has been shown that the use of RS in foods may have some benefits. Resistant starch, digestion of resistant-starch-containing foods have a number of health benefits for colon function but appear to have less effect on lipid-glucose metabolism. It has a positive effect on colon bacterial activity, promotes the growth of beneficial microbes, and reduces the activity of enzymes that are harmful to the digestive system. Under the influence of RS, increased SCFA production lowers the pH of the colon and stimulates bile acid secretion. The decreased pH protects against colon cancer and inhibits the conversion of primary and secondary bile acids, which are cytotoxic to intestinal cells. At the end of the review article, the relationships between RS and the colon microflora, its use as a prebiotic, and the relationship between RS and glucose metabolism are analysed. It was found that the use of RS in the diet might have benefits as it shortens the time it takes food to pass through the colon and increases the amount of stool. It was also found that the physicochemical properties of foods can directly affect the amount of RS and thereby the blood glucose levels and insulin response.


Sign in / Sign up

Export Citation Format

Share Document