scholarly journals Oxidative modification of ovalbumin.

1996 ◽  
Vol 43 (4) ◽  
pp. 661-672 ◽  
Author(s):  
S Olszowski ◽  
E Olszowska ◽  
T Stelmaszyńska ◽  
A Krawczyk ◽  
J Marcinkiewicz ◽  
...  
Keyword(s):  
Active Oxygen Species ◽  
Sulfhydryl Group ◽  
Oxidative Modification ◽  
Oxidation Products ◽  
Amino Groups ◽  
Covalent Bonds ◽  
Mixed Oxidation ◽  
Sds Page ◽  
Hplc Profiles ◽  
Model Protein

Stimulated neutrophils (PMNL) are a source of the active oxygen species: O2, H2O2 and HOCl/OCl- which in turn can act on proteins yielding a variety of mixed oxidation products. A system is proposed in which a model protein-ovalbumin (OVA) first undergoes chlorination by HOCl/OCl- and next is oxidised by H2O2. The modification of functional groups (-NH2, -SH, -S-S-, > C = O, Tyr and Trp) in OVA was monitored as well as their accessibility to promote aggregation. Chlorination resulted in additional inter- or intra -S-S- bond formation followed by a decrease in the total sulfhydryl group content. Amino groups were oxidised to carbonyl moieties with a concomitant acidic shift of pI. Formation of chlorotyrosine at the chlorination step was confirmed and its further H2O2-mediated transformation to bityrosine was demonstrated. It has also been confirmed that tryptophan, and not tyrosine, is the first target for chlorination. SDS/PAGE and HPLC profiles revealed that HOCl/OCl- chlorination promotes formation of aggregates stabilised by non covalent bonds. In conclusion, we suggest that a dramatic change in the OVA molecule structure begins when the molar excess of HOCl/OCl- is about 2 per one reactive group in OVA.

Abstract 177: Promotion Of Nitroso-redox Balance By Beta 3 Adrenoceptor Agonism: Therapeutic Implications For Cardiovascular Complications Of Diabetes

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Keyvan Karimi Galougahi ◽  
Chia-chi Liu ◽  
Alvaro Garcia ◽  
Natasha A Fry ◽  
Clare L Hawkins ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Cardiac Myocytes ◽  
Vascular Dysfunction ◽  
Pump Current ◽  
Redox Balance ◽  
Cardiovascular Complications ◽  
Oxidative Modification ◽  
Oxidation Products ◽  
Therapeutic Implications ◽  
Endothelial Nitric Oxide

Rationale: Disrupted balance between NO and O2.- is central in pathobiology of diabetes-induced cardiomyopathy and vascular dysfunction. We examined if stimulation of β3 adrenergic receptors (β3 ARs), coupled to endothelial nitric oxide synthase (eNOS) activation, would re-establish NO/O2.- balance, relieve oxidative inhibition of key caveolar proteins and protect against diabetes-induced cardiovascular dysfunction. Methods/Results: A hyperglycemic, hyperinsulinemic state was established in male White New Zealand rabbits by infusion of the insulin receptor antagonist S961 (12 μg/kg/h). Diabetes induced NADPH oxidase-dependent glutathionylation (GSS-) of the caveolar proteins Na+-K+ pump’s β1 subunit and eNOS in cardiac myocytes and aorta, an oxidative modification that inhibits the pump and uncouples eNOS. Consistent with this, diabetes was associated with reduced electrogenic Na+-K+ pump current in voltage-clamped cardiac myocytes and impaired endothelium-dependent vasorelaxation. Selective β3 AR agonist CL316243 (CL, 40 μg/kg/h) restored NO levels analysed by spin-trapping of NO-Fe(DETC)2 complexes; decreased diabetes-induced elevation in O2.- measured by HPLC analysis of dihydroethidium oxidation products, improved endothelium-dependent vasorelaxation, and restored the Na+-K+ pump function in cardiac myocytes. These effects were mediated by CL abolishing diabetes-induced increase in eNOS-GSS and β1-GSS through a decrease in forward reaction rate for glutathionylation by suppressing diabetes-induced NADPH oxidase activation, which was further amplified by promotion of de-glutathionylation via enhancement in association of glutaredoxine-1, the enzyme catalysing de-glutathionylation, with eNOS and Na+-K+ pump. Conclusion: β3 AR activation re-established nitroso-redox balance and relieved oxidative inhibition of key caveolar proteins in diabetes. β3 AR agonists are promising in treatment of diabetes-induced cardiovascular complications.

scholarly journals Removal of Organic Compounds with an Amino Group during the Nanofiltration Process

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Renata Żyłła ◽  
Magdalena Foszpańczyk ◽  
Magdalena Olak-Kucharczyk ◽  
Joanna Marszałek ◽  
Stanisław Ledakowicz
Keyword(s):  
Organic Compounds ◽  
Natural Organic Matter ◽  
Oxidation Product ◽  
Membrane Filtration ◽  
Separation Efficiency ◽  
Ph Value ◽  
Oxidation Products ◽  
Low Molecular Weight ◽  
Amino Group ◽  
Amino Groups

The research covered the process of nanofiltration of low molecular weight organic compounds in aqueous solution. The article presents the results of experiments on membrane filtration of compounds containing amino groups in the aromatic ring and comparing them with the results for compounds without amino groups. The research was carried out for several commercial polymer membranes: HL, TS40, TS80, DL from various manufacturers. It has been shown that the presence of the amino group and its position in relation to the carboxyl group in the molecule affects the retention in the nanofiltration process. The research also included the oxidation products of selected pharmaceuticals. It has been shown that 4-Amino-3,5-dichlorophenol—a oxidation product of diclofenac and 4-ethylbenzaldehyde—a oxidation product of IBU, show poor separation efficiency on the selected commercial membranes, regardless of the pH value and the presence of natural organic matter (NOM). It has been shown that pre-ozonation of natural river water can improve the retention of pollutants removed.

scholarly journals Selective oxidation of histidine residues in proteins or peptides through the copper(II)-catalysed autoxidation of glucosone

1992 ◽  
Vol 285 (2) ◽  
pp. 667-671 ◽  
Author(s):  
R Z Cheng ◽  
K Uchida ◽  
S Kawakishi
Keyword(s):  
Oxidative Damage ◽  
Active Oxygen Species ◽  
Oxidative Degradation ◽  
Imidazole Ring ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Selective Degradation ◽  
Sugar Moiety ◽  
Amadori Compound ◽  
Model Protein

Glucosone has been identified as the main intermediate sugar moiety product of the copper(II)-catalysed autoxidation of the Amadori compound [Kawakishi, Tsunehiro & Uchida (1991) Carbohydr. Res. 211, 167-171]. Oxidative fragmentation of the model protein, especially selective degradation of the histidine residue in protein or peptides mediated by the copper(II)-catalysed autoxidation of glucosone, is discussed in this paper. The oxidative damage to protein could be retarded by catalase (EC 1.11.1.16) and EDTA, while superoxide dismutase (EC 1.15.1.1) and hydroxyradical scavengers showed little effect. Through the process of the oxidative degradation of N-benzoylhistidine and other histidine-containing peptides, the oxidation of the imidazole ring in histidine caused by the glucosone-copper(II) system was the same as that by the ascorbate-copper(II) system. These facts suggest that the copper-catalysed autoxidation of glucosone could generate some active-oxygen species causing oxidative damage to protein similar to that caused by the ascorbate-copper(II) system.

scholarly journals Protein covalent modification of biologically active quinones

2004 ◽  
Vol 69 (11) ◽  
pp. 901-907 ◽  
Author(s):  
Dusan Sladic ◽  
Irena Novakovic ◽  
Zoran Vujcic ◽  
Tatjana Bozic ◽  
Natasa Bozic ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Chemical Modification ◽  
Covalent Modification ◽  
Biologically Active ◽  
Amino Groups ◽  
Sds Page ◽  
Protein Covalent

The avarone/avarol quinone/hydroquinone couple shows considerable antitumor activity. In this work, covalent modification of ?-lactoglobulin by avarone and its derivatives as well as by the synthetic steroidal quinone 2,5(10)-estradiene- 1,4,17-trione and its derivatives were studied. The techniques for studying chemical modification of ?-lactoglobulin by quinones were: UV/Vis spectrophotometry, SDS PAGE and isoelectrofocusing. SDS PAGE results suggest that polymerization of the protein occurs. It could be seen that the protein of 18 kD gives the bands of 20 kD, 36 kD, 40 kD, 45 kD, 64 kD and 128 kD depending on modification agent. The shift of the pI of the protein (5.4) upon modification toward lower values (from pI 5.0 to 5.3) indicated that lysine amino groups are the principal site of the reaction of ?-lactoglobulin with the quinones.

scholarly journals Protein Transfer in Mainstream and Sidestream Cigarette Smoke

2004 ◽  
Vol 21 (1) ◽  
pp. 9-14
Author(s):  
R Voisine ◽  
F Côté ◽  
J Verreault ◽  
A Porter
Keyword(s):  
Cigarette Smoke ◽  
Tobacco Smoke ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Solvent System ◽  
Protein Transfer ◽  
Western Immunoblotting ◽  
Sidestream Smoke ◽  
Sds Page ◽  
Model Protein

AbstractProtein transfer in tobacco smoke has been studied using the protease, Savinase™, as a model protein. Mainstream and sidestream smoke were collected from cigarettes to which Savinase had been added at various concentrations. Savinase was extracted from the smoke condensate with an organic solvent system before being precipitated and further identified by denaturing polyacrylamide gel electrophoresis (SDS-PAGE) and Western immunoblotting. The detection limit of the method, based on addition of Savinase to the smoke condensate, was 25 µg in mainstream and 100 µg in sidestream smoke. At a Savinase concentration of 6000 µg per gram of tobacco, the methodology allows the detection of protein transfer as low as 0.009% and 0.054% in mainstream and sidestream smoke, respectively. Using this approach, it was shown that there is no detectable Savinase in the mainstream and sidestream smoke of filtered and unfiltered cigarettes containing up to 6000 µg of Savinase per gram of tobacco. These facts strongly suggest that there is no significant transfer of protein from tobacco into cigarette smoke.

scholarly journals Lipoxygenase treatment render low-density lipoprotein susceptible to Cu2+-catalysed oxidation

1996 ◽  
Vol 314 (2) ◽  
pp. 577-585 ◽  
Author(s):  
Achim LASS ◽  
Jutta BELKNER ◽  
Hermann ESTERBAUER ◽  
Hartmut KÜHN
Keyword(s):  
Low Density Lipoprotein ◽  
Complex Mixture ◽  
Density Lipoprotein ◽  
Oxidative Modification ◽  
Oxidation Products ◽  
Ldl Oxidation ◽  
Foam Cell Formation ◽  
Low Density ◽  
Catalysed Oxidation ◽  
Lag Period

Oxidative modification of low-density lipoprotein (LDL) has been implicated in foam-cell formation at all stages of atherosclerosis. Since transition metals and mammalian 15-lipoxygenases are capable of oxidizing LDL to its atherogenic form, a concerted action of these two catalysts in atherogenesis has been suggested. Cu2+-catalysed LDL oxidation is characterized by a kinetic lag period in which the lipophilic antioxidants are decomposed and by a complex mixture of unspecific oxidation products. We investigated the kinetics of the 15-lipoxygenase-catalysed oxygenation of LDL and found that the enzyme is capable of oxidizing LDL in the presence of the endogenous lipophilic antioxidants. In contrast with the Cu2+-catalysed reaction, no kinetic lag phase was detected. The pattern of products formed during short-term incubations was highly specific, with cholesterol-esterified (13S)-hydroperoxy-(9Z,11E)-octadecadienoic acid being the major product. However, after long-term incubations the product pattern was less specific. Preincubation with 15-lipoxygenase rendered human LDL more susceptible to Cu2+-catalysed oxidation as indicated by a dramatic shortening of the lag period. Addition of Cu2+ to lipoxygenase-treated LDL led to a steep decline in its antioxidant content and to a greatly reduced lag period. Interestingly, if normalized to a comparable hydroperoxide content, autoxidation and addition of exogenous hydroperoxy fatty acids both failed to overcome the lag period. The local peroxide concentrations in various LDL subcompartments will be discussed as a possible reason for this unexpected behaviour.

scholarly journals THE ROLE OF PROTEIN OXIDATIVE MODIFICATION IN REDOX-REGULATION OF CASPASE-3 ACTIVITY IN BLOOD LYMPHOCYTES DURING OXIDATIVE STRESS IN VITRO

2015 ◽  
Vol 14 (6) ◽  
pp. 61-67
Author(s):  
O. L. Nosareva ◽  
Ye. A. Stepovaya ◽  
N. V. Ryazantseva ◽  
Ye. V. Shakhristova ◽  
O. N. Vesnina ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caspase 3 ◽  
Active Oxygen Species ◽  
Protein Carbonyl ◽  
Oxidative Modification ◽  
Blood Lymphocytes ◽  
Glutathione Concentration ◽  
Carbonyl Derivatives ◽  
Sh Group

The formation of oxidative stress lies at the heart of many frequent and socially-important diseases. Blood lymphocytes are the cells which provide immunological control of our organism. As a result of their function implementation blood lymphocytes contact with different endogenic and exogenic factors, which can lead to active oxygen species production activation, macromolecules oxidative modification and to cell survival alteration. At the present time it is essential to expand and deepen the fundamental knowledge of blood lymphocytes apoptosis regulation peculiarities. The research objective was to establish the interaction among alterations of glutathione system condition, carbonylation level, protein glutathionylation and caspase-3 activity in blood lymphocytes during oxidative stress in vitro.Material and Methods. The material for research was blood lymphocytes cultivated with addition of hydrogen peroxide in final concentration of 0,5 mmol and/or protein SH-group inhibitor N-ethylmaleimide – 5 mmol, protector – 5 mmol – 1,4-dithioerythritol. Reduced, oxidized and protein-bound glutathione concentration was measured by method of spectropho-tometry, additionally, the ratio size of reduced to oxidized thiol fraction was estimated. With help of enzymoimmunoassay the level of protein carbonyl derivatives was evaluated; caspase-3 activity was registered by spectrofluorometric method.Results. Protein SH-group blocking in blood lymphocytes during oxidative stress in vitro was accompanied by protein-bound glutathione concentration rapid decrease in connection with increase of protein carbonyl derivatives content and caspase-3 activity. Protein SH-group protection in blood lymphocytes during oxidative stress in vitro was accompanied by concentration increase of protein-bound glutathione and protein carbonyl derivatives under comparable values of enzyme activity under study.Conclusion. The carried out research shows that caspase-3 and protein-bound glutathione are the molecular targets of selective control over programmed cell death. The received indices of caspase-3 activity change and protein-bound glutathione concentration alteration in blood lymphocytes during oxidative stress in vitro can be used when elaborating target therapy approaches to diseases accompanied by apoptosis disregulation.

scholarly journals Cuminum cyminum methanolic extract prevents oxidative modification of low density lipoproteins: Preliminary evidence on its anti-atherosclerotic potential

2018 ◽  
Vol 7 (1) ◽  
pp. 79-83
Author(s):  
Ranjitsinh Devkar ◽  
◽  
Kiran Lagu ◽  
Jaymesh Thadani ◽  
Kavita Shirsath ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Ex Vivo ◽  
Lipid Hydroperoxide ◽  
Oxidation Kinetic ◽  
Preliminary Evidence ◽  
Oxidative Modification ◽  
Oxidation Products ◽  
Ldl Oxidation ◽  
Efficient Treatment ◽  
Cuminum Cyminum

The significance of oxidative modification of LDL in the pathogenesis of atherosclerosis and the lack of efficient treatment intervention has led researchers to develop an effective therapy based on natural antioxidants. The present study provides preliminary evidence in support of the anti-atherosclerotic potential of methanolic extract of Cuminum cyminum L. (CC). We found that CC inhibited Cu2+ -mediated LDL oxidation as demonstrated by the ex vivo LDL oxidation kinetic study, the LDL oxidation products (malondialdehyde, lipid hydroperoxide and protein carbonyl), and ApoB fragmentation assay. It can be concluded that, CC efficiently alleviates experimentally induced oxidative changes and modifications of LDL. Since oxidative changes in LDL are prerequisite to onset of atherogenic changes, this study provides preliminary evidence on anti-atherosclerotic potential of CC

scholarly journals Characterization of bovine serum albumin glycated with glucose, galactose and lactose.

2008 ◽  
Vol 55 (3) ◽  
pp. 491-497 ◽  
Author(s):  
Ana Irene Ledesma-Osuna ◽  
Gabriela Ramos-Clamont ◽  
Luz Vázquez-Moreno
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Lectin Binding ◽  
Enzymatic Reaction ◽  
Biological Research ◽  
Binding Assays ◽  
Amino Groups ◽  
Sds Page ◽  
Biological Recognition

The non-enzymatic reaction between reducing sugars and proteins, known as glycation, has received increased attention from nutritional and medical research. In addition, there is a large interest in obtaining glycoconjugates of pure well-characterized oligosaccharides for biological research. In this study, glycation of bovine serum albumin (BSA) by d-glucose, d-galactose and d-lactose under dry-heat at 60 degrees C for 30, 60, 120, 180 or 240 min was assessed and the glycated products studied in order to establish their biological recognition by lectins. BSA glycation was monitored using gel electrophoresis, determination of available amino groups and lectin binding assays. The BSA molecular mass increase and glycation sites were investigated by mass spectrometry and through digestion with trypsin and chymotrypsin. Depending on time and type of sugar, differences in BSA conjugation were achieved. Modified BSA revealed reduction of amino groups' availability and slower migration through SDS/PAGE. d-galactose was more reactive than d-glucose or d-lactose, leading to the coupling of 10, 3 and 1 sugar residues, respectively, after 120 minutes of reaction. BSA lysines (K) were the preferred modified amino acids; both K256 and K420 appeared the most available for conjugation. Only BSA-lactose showed biological recognition by specific lectins.

The Action of Periodic Acid and its Salts on Wool

1969 ◽  
Vol 39 (9) ◽  
pp. 858-865 ◽  
Author(s):  
A. Kantouch ◽  
A. Bendak
Keyword(s):  
Free Amino ◽  
Binding Capacity ◽  
Periodic Acid ◽  
Periodate Oxidation ◽  
Oxidation Products ◽  
Amino Groups ◽  
Periodate Treatment ◽  
Aldehyde Oxidation ◽  
Sulfur Containing ◽  
Amide Content

Sulfur and nitrogen of periodate-oxidized wool as well as resulting oxidation compounds were investigated. It was found that sulfur content decreased gradually with oxidation. The greatest part of this decrease was found in solution either as sulfuric acid or as sulfur-containing proteinic products. Nitrogen content of wool is nearly unaffected by periodate treatment. Aldehyde oxidation products condense with amino groups of wool, as indicated by infrared spectroscopy. The acid-binding capacity of periodate-treated wool decreased with oxidation, most probably because of the blocking of free amino groups. The amide content as well as the base-binding capacity increase with oxidation. A reaction mechanism for periodate oxidation with wool is suggested.

Sign in / Sign up

Export Citation Format

Share Document