Search results for " enzyme"

Repair of oxidatively generated DNA damage in Cockayne syndrome

2013

Defects in the repair of endogenously (especially oxidatively) generated DNA modifications and the resulting genetic instability can potentially explain the clinical symptoms of Cockayne syndrome (CS), a hereditary disease characterized by developmental defects and neurological degeneration. In this review, we describe the evidence for the involvement of CSA and CSB proteins, which are mutated in most of the CS patients, in the repair and processing of DNA damage induced by reactive oxygen species and the implications for the induction of cell death and mutations. Taken together, the data demonstrate that CSA and CSB, in addition to their established role in transcription-coupled nucleotide…

Correlation between superoxide dismutase, glutathione peroxidase and catalase in isolated rat hepatocytes during fetal development

1981

Abstract Superoxide dismutase, glutathione peroxidase and catalase activities were determined in isolated fetal rat hepatocytes of various ages and compared with the values of neonatal and adult cells. The developmental pattern of superoxide dismutase and glutathione peroxidase were very similar with a low constant activity in the fetal cells and a postnatal burst. On the contrary catalase begins to increase already since the 18th day of the fetal life. The results suggest a functional correlation of superoxide dismutase and glutathione peroxidase in the antioxidative enzyme defense of liver cells.

Lifelong soya consumption in males does not increase lifespan but increases health span under a metabolic stress such as type 2 diabetes mellitus.

2021

Soya consumption can decrease oxidative stress in animal models. Moreover, phytoestrogens such as genistein, present in soya, can mimic some of the beneficial effects of estrogens and are devoid of significant side effects, such as cancer. In this study, we have performed a controlled lifelong study with male OF1 mice that consumed either a soya-free diet or a soya-rich diet. We show that, although we found an increase in the expression and activity of antioxidant enzymes in soya-consuming mice, it did not increase lifespan. We reasoned that the soya diet could not increase lifespan in a very healthy population, but perhaps it could extend health span in stressed animals such as type 2 diab…

Relationships between oxygen concentration and patterns of energy metabolism in the rotifer Brachionus plicatilis

1992

Abstract 1. 1. Activities of 10 enzymes and accumulation of two metabolites under experimental hypoxia were investigated in the rotifer Brachionus plicatilis . 2. 2. Pyruvate kinase (PK), lactate dehydrogenase (LDH), malic enzyme (ME), phosphoenolpyruvate carboxykinase (PEPCK), malate dehydrogenase (MDH) and fumarase (FUM) activities showed great increase at low oxygen levels. Alcohol dehydrogenase (ADH) activity was not detected. 3. 3. Alanine concentration showed an increase with low oxygen concentrations, while alanine aminotransferase (GTP) showed a slight activity increase with oxygen levels. The high alanine concentration was interpreted as enhanced proteolysis. 4. 4. Our results show…

Aldosterone synthase activity in the Y-1 adrenal cell line.

1995

The Y-1 adrenal cell line was shown to produce 20 alpha-dihydroaldosterone from deoxycorticosterone. This compound was identified by GC-MS by comparison with the previously synthesized reference compound. Two other 18-hydroxylated metabolites were identified as 11 beta,18-dihydroxy-20 alpha-dihydroprogesterone from endogenous cholesterol and 18-hydroxy-20 alpha-dihydro-11-dehydrocorticosterone from DOC. The conditions necessary for the synthesis of these compounds are culturing in 20% serum-supplemented medium and repeated incubations with the substrate. The production of 11 beta-hydroxylated steroids and that of 18-oxygenated steroids is stimulated differently by ACTH and angiotensin II su…

MGMT: Key node in the battle against genotoxicity, carcinogenicity and apoptosis induced by alkylating agents

2007

O(6)-methylguanine-DNA methyltransferase (MGMT) plays a crucial role in the defense against alkylating agents that generate, among other lesions, O(6)-alkylguanine in DNA (collectively termed O(6)-alkylating agents [O(6)AA]). The defense is highly important, since O(6)AA are common environmental carcinogens, are formed endogenously during normal cellular metabolism and possibly inflammation, and are being used in cancer therapy. O(6)AA induced DNA damage is subject to repair, which is executed by MGMT, AlkB homologous proteins (ABH) and base excision repair (BER). Although this review focuses on MGMT, the mechanism of repair by ABH and BER will also be discussed. Experimental systems, in wh…

Modificētu enzīmu dizains proteīnu deglikācijai

2022

Fruktozila peptīdu oksidāzes, pazīstamas arī kā Amadoriāzes, ir enzīmu saime, kas katalizē fruktozilaminoskābju deglikozilāciju. Šī darba mērķis ir novērtēt termālo stabilitāti un enzimātisko aktivitāti Amadoriāzes enzīma mutantiem, C16 un D02, kurus izstrādāja ārvalstu kolēģi, izmantojot skaitļošanas metodes. Darba gaitā tika veikta veikta ekspresija E. coli šūnās un proteīnu attīrīšana, izmantojot šķīdumu hromatogrāfiju. Tika veikta proteīnu analīze, izmantojot biofizikālu un bioķīmisku analīžu metodes - termiskās nobīdes, cirkulārā dihroisma un enzimātiskās aktivitātes testus. Rezultāti uzrādīja termostabilitātes un viršas punktu palielināšanos abiem mutantiem, enzimātiskās aktivitātes u…

Expression of proteolitic enzymes in induced angiogenesis

2008

Angiogenesis (growth of new blood vessels) plays a key role in tissue repair, such as in cancer progression (Folkman 1995. New Engl. J. Med. 333, 1757-63). At the beginning of the process is observed the matrix degradation and endothelial cells (ECs) migration inside to the connective tissue in proximity of vessel walls. During angiogenesis several modifications occurs at plasma membrane level; a redistribution of cell-cell and cell-matrix adhesion molecules (Bazzoni et al 1999), such as an increased expression of several proteolytic enzymes, including MMPs and serine proteases, as plasminogen activators and SIMPs, were observed (Ghersi et al. 2006. Cancer Res. 66, 4652-61; Ghersi 2008 Fron…

Role of MT1-MMP in cell-cell contact formation of endothelial cells

2008

Focus on clinical practice: angiotensin-converting enzyme 2 and corona virus disease 2019: pathophysiology and clinical implications.

2020

: ACE2 receptor has a broad expression pattern in the cellular membrane and provides a protective action against the development of cardiovascular diseases. Recently, this enzyme has become of extreme interest during the pandemic infection of COVID-19 (coronavirus disease 2019). This virus invades alveolar epithelium and cardiomyocytes using ACE2 as a transmembrane receptor. ACE2 is a counter-regulatory peptide that degrades Ang II into Ang 1-7, thereby attenuating the biological effects of the AT1 receptor. The binding between the spike protein of COVID-19 and the enzyme is crucial for the virus to enter the target cells, but whether an increase in ACE2 activity could facilitate the infect…