scholarly journals Selenoproteins

2015 ◽  
Vol 69 (1-2) ◽  
pp. 75-89
Author(s):  
Svetlana Milanovic ◽  
Ivan Jovanovic ◽  
Olivera Valcic
Keyword(s):  
Hydrogen Peroxide ◽  
Trace Elements ◽  
Amino Acid ◽  
Integral Functional ◽  
Physiological Role ◽  
The Body ◽  
Essential Trace Element ◽  
Iodothyronine Deiodinases ◽  
Organic Hydroperoxides ◽  
Functional Part

Selenium is an essential trace element with multi significant role in the body. In contrast to other trace elements that appear as cofactors of certain enzymes, its physiological role is directly related to functions of proteins in composition of which it is cotranslationally installed by atypical amino acid selenocysteine. The group of proteins, in which composition selenocysteine is an integral functional part of polypeptides, are referred to as selenoproteins. The first enzyme that has been proven to have selenocysteine incorporated in its composition, is glutathione peroxidase (GPx). So far there have been identified 5 isoenzyme forms of GPx which reduce hydrogen peroxide and organic hydroperoxides, protecting cells from oxidative damage. Iodothyronine deiodinases (ID) are among the most important selenopoteins, being responsible for both activation and deactivation of thyroid hormones. So far there have been found over twenty selenoproteins, but only for some of them a physiological role is known.

scholarly journals Hydrogen Indirectly Suppresses Increases in Hydrogen Peroxide in Cytoplasmic Hydroxyl Radical-Induced Cells and Suppresses Cellular Senescence

2019 ◽  
Vol 20 (2) ◽  
pp. 456 ◽  
Author(s):  
Takahiro Sakai ◽  
Ryosuke Kurokawa ◽  
Shin-ichi Hirano ◽  
Jun Imai
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Cellular Senescence ◽  
Physiological Role ◽  
Lipid Peroxide ◽  
Gut Bacteria ◽  
The Body ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Plant Fibers

Bacteria inhabiting the human gut metabolize microbiota-accessible carbohydrates (MAC) contained in plant fibers and subsequently release metabolic products. Gut bacteria produce hydrogen (H2), which scavenges the hydroxyl radical (•OH). Because H2 diffuses within the cell, it is hypothesized that H2 scavenges cytoplasmic •OH (cyto •OH) and suppresses cellular senescence. However, the mechanisms of cyto •OH-induced cellular senescence and the physiological role of gut bacteria-secreted H2 have not been elucidated. Based on the pyocyanin-stimulated cyto •OH-induced cellular senescence model, the mechanism by which cyto •OH causes cellular senescence was investigated by adding a supersaturated concentration of H2 into the cell culture medium. Cyto •OH-generated lipid peroxide caused glutathione (GSH) and heme shortage, increased hydrogen peroxide (H2O2), and induced cellular senescence via the phosphorylation of ataxia telangiectasia mutated kinase serine 1981 (p-ATMser1981)/p53 serine 15 (p-p53ser15)/p21 and phosphorylation of heme-regulated inhibitor (p-HRI)/phospho-eukaryotic translation initiation factor 2 subunit alpha serine 51 (p-eIF2α)/activating transcription factor 4 (ATF4)/p16 pathways. Further, H2 suppressed increased H2O2 by suppressing cyto •OH-mediated lipid peroxide formation and cellular senescence induction via two pathways. H2 produced by gut bacteria diffuses throughout the body to scavenge cyto •OH in cells. Therefore, it is highly likely that gut bacteria-produced H2 is involved in intracellular maintenance of the redox state, thereby suppressing cellular senescence and individual aging. Hence, H2 produced by intestinal bacteria may be involved in the suppression of aging.

scholarly journals Involvement of d-amino acid oxidase in elimination of free d-amino acids in mice

1989 ◽  
Vol 257 (1) ◽  
pp. 291-292 ◽  
Author(s):  
Y Nagata ◽  
R Konno ◽  
Y Yasumura ◽  
T Akino
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Physiological Role ◽  
The Body ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Kidney Liver ◽  
Amino Acid Concentrations ◽  
Serum And Urine

The physiological role of D-amino acid oxidase was investigated by using mutant ddY/DAO- mice lacking the enzyme. Free D-amino acid concentrations in the mutant mice were significantly higher than those of control ddY/DAO+ mice in kidney, liver, lung, heart, brain, erythrocytes, serum and urine. The results suggest that the enzyme is involved in the catabolism of free D-amino acids in the body, and that free D-amino acids are also excreted into urine.

Determination of trace element composition. Clinical and laboratory algorithms. Rationale for the determination of trace elements in humans

2020 ◽  
pp. 48-54
Author(s):  
Vitaliya Morozova
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Chemical Elements ◽  
Physiological Role ◽  
Trace Element Composition ◽  
Element Composition ◽  
The Body ◽  
Laboratory Diagnostics ◽  
Endocrine Regulation

There are more than 70 chemical elements in the human body. To date, the need for more than 20 trace elements has been determined: deficiency in them leads to disruption of the neural, immune and endocrine regulation and adaptive potential, increases the risk of infectious diseases and development of their chronicity. A prolonged absence of certain nutrients in the diet, or vice versa, excess of them in soil and water, can cause irreversible changes in the body. The article discusses physiological role of minerals, macro and micronutrients, features of their metabolism, content standards, causes of their shortage in the diet. Recommendations on the choice of material for the study of the trace element composition are given and possibilities of modern laboratory diagnostics are presented.

Impairment of Platelet Aggregation by Echis colorata Venom Mediated by L-Amino Acid Oxidase or H2O2

1982 ◽  
Vol 48 (03) ◽  
pp. 277-282 ◽  
Author(s):  
I Nathan ◽  
A Dvilansky ◽  
T Yirmiyahu ◽  
M Aharon ◽  
A Livne
Keyword(s):  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Platelet Aggregation ◽  
Snake Venom ◽  
Oxidase Activity ◽  
Enzyme Preparation ◽  
Acid Oxidase ◽  
Crude Venom ◽  
Amino Acid Oxidase ◽  
Hemostatic Disorders

SummaryEchis colorata bites cause impairment of platelet aggregation and hemostatic disorders. The mechanism by which the snake venom inhibits platelet aggregation was studied. Upon fractionation, aggregation impairment activity and L-amino acid oxidase activity were similarly separated from the crude venom, unlike other venom enzymes. Preparations of L-amino acid oxidase from E.colorata and from Crotalus adamanteus replaced effectively the crude E.colorata venom in impairment of platelet aggregation. Furthermore, different treatments known to inhibit L-amino acid oxidase reduced in parallel the oxidase activity and the impairment potency of both the venom and the enzyme preparation. H2O2 mimicked characteristically the impairment effects of L-amino acid oxidase and the venom. Catalase completely abolished the impairment effects of the enzyme and the venom. It is concluded that hydrogen peroxide formed by the venom L-amino acid oxidase plays a role in affecting platelet aggregation and thus could contribute to the extended bleeding typical to persons bitten by E.colorata.

An ESR study of the peroxidase reaction catalyzed by human methaemoglobin and methaemoglobin-haptoglobin complex

1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Peroxidase Activity ◽  
Amino Acid Analysis ◽  
Superoxide Radical ◽  
Esr Spectra ◽  
The Other ◽  
Delocalized Electron

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.

scholarly journals Role of Chiral Configuration in the Photoinduced Interaction of D- and L-Tryptophan with Optical Isomers of Ketoprofen in Linked Systems

2021 ◽  
Vol 22 (12) ◽  
pp. 6198
Author(s):  
Aleksandra A. Ageeva ◽  
Ilya M. Magin ◽  
Alexander B. Doktorov ◽  
Victor F. Plyusnin ◽  
Polina S. Kuznetsova ◽  
...  
Keyword(s):  
Amino Acid ◽  
Excited States ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Dipole Interaction ◽  
The Body ◽  
Model Systems ◽  
Optical Isomers ◽  
Amino Acid Properties ◽  
Parkinson’S Diseases

The study of the L- and D-amino acid properties in proteins and peptides has attracted considerable attention in recent years, as the replacement of even one L-amino acid by its D-analogue due to aging of the body is resulted in a number of pathological conditions, including Alzheimer’s and Parkinson’s diseases. A recent trend is using short model systems to study the peculiarities of proteins with D-amino acids. In this report, the comparison of the excited states quenching of L- and D-tryptophan (Trp) in a model donor–acceptor dyad with (R)- and (S)-ketoprofen (KP-Trp) was carried out by photochemically induced dynamic nuclear polarization (CIDNP) and fluorescence spectroscopy. Quenching of the Trp excited states, which occurs via two mechanisms: prevailing resonance energy transfer (RET) and electron transfer (ET), indeed demonstrates some peculiarities for all three studied configurations of the dyad: (R,S)-, (S,R)-, and (S,S)-. Thus, the ET efficiency is identical for (S,R)- and (R,S)-enantiomers, while RET differs by 1.6 times. For (S,S)-, the CIDNP coefficient is almost an order of magnitude greater than for (R,S)- and (S,R)-. To understand the source of this difference, hyperpolarization of (S,S)-and (R,S)- has been calculated using theory involving the electron dipole–dipole interaction in the secular equation.

scholarly journals Rap1a Overlaps the AGE/RAGE Signaling Cascade to Alter Expression of α-SMA, p-NF-κB, and p-PKC-ζ in Cardiac Fibroblasts Isolated from Type 2 Diabetic Mice

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 557
Author(s):  
Stephanie D. Burr ◽  
James A. Stewart
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Hydrogen Peroxide ◽  
Cardiac Fibroblasts ◽  
The Body ◽  
Signaling Cascade ◽  
Diabetic Mice ◽  
Pkc Ζ ◽  
Type 2 Diabetic

Cardiovascular disease, specifically heart failure, is a common complication for individuals with type 2 diabetes mellitus. Heart failure can arise with stiffening of the left ventricle, which can be caused by “active” cardiac fibroblasts (i.e., myofibroblasts) remodeling the extracellular matrix (ECM). Differentiation of fibroblasts to myofibroblasts has been demonstrated to be an outcome of AGE/RAGE signaling. Hyperglycemia causes advanced glycated end products (AGEs) to accumulate within the body, and this process is greatly accelerated under chronic diabetic conditions. AGEs can bind and activate their receptor (RAGE) to trigger multiple downstream outcomes, such as altering ECM remodeling, inflammation, and oxidative stress. Previously, our lab has identified a small GTPase, Rap1a, that possibly overlaps the AGE/RAGE signaling cascade to affect the downstream outcomes. Rap1a acts as a molecular switch connecting extracellular signals to intracellular responses. Therefore, we hypothesized that Rap1a crosses the AGE/RAGE cascade to alter the expression of AGE/RAGE associated signaling proteins in cardiac fibroblasts in type 2 diabetic mice. To delineate this cascade, we used genetically different cardiac fibroblasts from non-diabetic, diabetic, non-diabetic RAGE knockout, diabetic RAGE knockout, and Rap1a knockout mice and treated them with pharmacological modifiers (exogenous AGEs, EPAC, Rap1a siRNA, and pseudosubstrate PKC-ζ). We examined changes in expression of proteins implicated as markers for myofibroblasts (α-SMA) and inflammation/oxidative stress (NF-κB and SOD-1). In addition, oxidative stress was also assessed by measuring hydrogen peroxide concentration. Our results indicated that Rap1a connects to the AGE/RAGE cascade to promote and maintain α-SMA expression in cardiac fibroblasts. Moreover, Rap1a, in conjunction with activation of the AGE/RAGE cascade, increased NF-κB expression as well as hydrogen peroxide concentration, indicating a possible oxidative stress response. Additionally, knocking down Rap1a expression resulted in an increase in SOD-1 expression suggesting that Rap1a can affect oxidative stress markers independently of the AGE/RAGE signaling cascade. These results demonstrated that Rap1a contributes to the myofibroblast population within the heart via AGE/RAGE signaling as well as promotes possible oxidative stress. This study offers a new potential therapeutic target that could possibly reduce the risk for developing diabetic cardiovascular complications attributed to AGE/RAGE signaling.

scholarly journals Amadori rearrangement products as potential biomarkers for inborn errors of amino-acid metabolism

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Rianne E. van Outersterp ◽  
Sam J. Moons ◽  
Udo F. H. Engelke ◽  
Herman Bentlage ◽  
Tessa M. A. Peters ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
The Body ◽  
Inborn Errors ◽  
Primary Metabolite ◽  
Diagnostic Strategies ◽  
Ion Spectroscopy ◽  
Disease Biomarkers ◽  
Amadori Rearrangement

AbstractThe identification of disease biomarkers plays a crucial role in developing diagnostic strategies for inborn errors of metabolism and understanding their pathophysiology. A primary metabolite that accumulates in the inborn error phenylketonuria is phenylalanine, however its levels do not always directly correlate with clinical outcomes. Here we combine infrared ion spectroscopy and NMR spectroscopy to identify the Phe-glucose Amadori rearrangement product as a biomarker for phenylketonuria. Additionally, we find analogous amino acid-glucose metabolites formed in the body fluids of patients accumulating methionine, lysine, proline and citrulline. Amadori rearrangement products are well-known intermediates in the formation of advanced glycation end-products and have been associated with the pathophysiology of diabetes mellitus and ageing, but are now shown to also form under conditions of aminoacidemia. They represent a general class of metabolites for inborn errors of amino acid metabolism that show potential as biomarkers and may provide further insight in disease pathophysiology.

Effect of hydrogen peroxide on d-amino acid oxidase from Rhodotorula gracilis

2000 ◽  
Vol 27 (3-5) ◽  
pp. 234-239 ◽  
Author(s):  
Isabel de la Mata ◽  
Fernando Ramón ◽  
Virginia Obregón ◽  
Ma Pilar Castillón ◽  
Carmen Acebal
Keyword(s):  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Rhodotorula Gracilis

EFFECTS OF LYSINE INFUSION PER ABOMASUM OF STEERS FED CONTINUOUSLY

1972 ◽  
Vol 52 (4) ◽  
pp. 681-687 ◽  
Author(s):  
R. J. BOILA ◽  
T. J. DEVLIN
Keyword(s):  
Amino Acid ◽  
Crude Protein ◽  
Dry Matter ◽  
Latin Square ◽  
Linear Increase ◽  
The Body ◽  
The Other ◽  
Body Tissue ◽  
Rumen Microorganisms

Four dairy steers were allotted to four lysine infusion levels in a 4 × 4 latin square design and fed an 11.5% crude protein (90% dry matter (DM)) diet continuously (10-min intervals every 24 hr). Lysine hydrochloride equivalent to 0.0, 3.0, 6.0, and 9.0 g lysine per day was infused per abomasum. When 9 g lysine were infused per day, the percent of absorbed nitrogen (N) retained was significantly (P < 0.05) reduced; urinary N excretion as a percentage of N intake and plasma-free lysine were increased significantly compared with the other three infusion treatments. The infusion of 9 g lysine per day apparently exceeded the body tissue requirements for this amino acid and the excess N was excreted in the urine. A possibility of lysine being limiting (0.28% lysine of a 100% DM diet) was apparently offset by the synthesis of lysine by rumen microorganisms, which increased the dietary lysine two- to threefold. Increased levels of infused lysine did not result in a linear increase of lysine in the abomasum. With 3 g per day lysine infusion rumen ammonia and N retentions were high. However, a smaller amount of N reached the abomasum with steers on this treatment.

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