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Silent information regulator sirtuin 1 ameliorates acute liver failure via the p53/glutathione peroxidase 4/gasdermin D axis 被引量:6
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作者 Xing-Nian Zhou Quan Zhang +6 位作者 Hong Peng Yu-Jie Qin Yu-Hong Liu Lu Wang Ming-Liang Cheng Xin-Hua Luo Hong Li 《World Journal of Gastroenterology》 SCIE CAS 2024年第11期1588-1608,共21页
BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple b... BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple biological processes,including cellular senescence,apoptosis,sugar and lipid metabolism,oxidative stress,and inflammation.AIM To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms.METHODS This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)testing.C57BL/6 mice were also intraperitoneally pretreated with SIRT1,p53,or glutathione peroxidase 4(GPX4)inducers and inhibitors and injected with lipopolysaccharide(LPS)/D-galactosamine(D-GalN)to induce ALF.Gasdermin D(GSDMD)^(-/-)mice were used as an experimental group.Histological changes in liver tissue were monitored by hematoxylin and eosin staining.ALT,AST,glutathione,reactive oxygen species,and iron levels were measured using commercial kits.Ferroptosis-and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction.SIRT1,p53,and GSDMD were assessed by immunofluorescence analysis.RESULTS Serum AST and ALT levels were elevated in patients with ALF.SIRT1,solute carrier family 7a member 11(SLC7A11),and GPX4 protein expression was decreased and acetylated p5,p53,GSDMD,and acyl-CoA synthetase long-chain family member 4(ACSL4)protein levels were elevated in human ALF liver tissue.In the p53 and ferroptosis inhibitor-treated and GSDMD^(-/-)groups,serum interleukin(IL)-1β,tumour necrosis factor alpha,IL-6,IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated.In mice with GSDMD knockout,p53 was reduced,GPX4 was increased,and ferroptotic events(depletion of SLC7A11,elevation of ACSL4,and iron accumulation)were detected.In vitro,knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels,the cytostatic rate,and GSDMD expression,restoring SLC7A11 depletion.Moreover,SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group,accompanied by reduced p53,GSDMD,and ACSL4,and increased SLC7A11 and GPX4.Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalNinduced in vitro and in vivo models.CONCLUSION SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF. 展开更多
关键词 Silent information regulator sirtuin 1 Ferroptosis PYROPTOSIS p53/glutathione peroxidase 4/gasdermin D Acute liver failure
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Evaluation of combined detection of nuclear factor erythroid 2-related factor 2 and glutathione peroxidase 4 in primary hepatic carcinoma and preliminary exploration of pathogenesis
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作者 JIE DUAN AIDONG GU +5 位作者 WEI CHEN CHANGHAO CHEN FANGNAN SONG FAXI CHEN FANGFANG JIANG HUIWEN XING 《BIOCELL》 SCIE 2023年第12期2609-2615,共7页
This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2... This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2 and GPX4 in peripheral blood of patients with PHC was determined to analyze the diagnostic value of the two combined for PHC.The prognostic significance of NRF2 and GPX4 was evaluated by 3-year followup.Human liver epithelial cells THLE-2 and human hepatocellular carcinoma cells HepG2 were purchased,and the expression of NRF2 and GPX4 in the cells was determined.NRF2 and GPX4 aberrant expression vectors were constructed and transfected into HepG2,and changes in cell proliferation and invasion capabilities were observed.Results:The expression of NRF2 and GPX4 in patients with PHC was higher than that in patients with LC or VH(p<0.05),and the two indicators combined was excellent in diagnosing PHC.Moreover,patients with high expression of NRF2 and GPX4 had a higher risk of death(p<0.05).In in vitro experiments,both NRF2 and GPX4 expression was elevated in HepG2(p<0.05).HepG2 activity was enhanced by increasing the expression of the two,vice versa(p<0.05).Conclusion:NRF2 and GPX4 combined is excellent in diagnosing PHC,and promotes the malignant development of PHC. 展开更多
关键词 Nuclear factor erythroid 2 Related factor 2 Glutathione peroxidase 4 Primary hepatic carcinoma Clinical significance Mechanism of action PATHOGENESIS
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Glutathione peroxidase mimicry of diphenyl diselenide: Plausible contribution of proteins’ thiols
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作者 Ebenezer Morayo Ale Steve Osagie Asuelimen Olawale Otitoju 《Toxicology Advances》 2023年第2期14-20,共7页
Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organ... Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organoselenium whose GPx mimetic property has been suggested to rely on the oxidation of non-protein or protein thiols critical to the activities of some sulfhydryl enzymes.This study,therefore investigated the GPx mimic/antioxidant property of DPDS as well as the role of thiols of two key sulfhydryl enzymes,cerebral Na^(+)/K^(+)-ATPase(sodium pump)and hepatic delta-aminolevulinic acid dehydratase(δ-ALAD)in the GPx mimicry of DPDS.Albino Wistar rats were euthanized,and the liver and brain were removed and used to assay for the effect of DPDS on lipid peroxidation induced by two prooxidants[Fe2^(+)(10μM)and H2O2,(1 mM)]as well as the activities of the sulfhydryl enzymes.The results revealed that DPDS profoundly(P<0.05)counteracted Fe2^(+)and H2O2-induced lipid peroxidation in the rats’hepatic and cerebral tissues.Furthermore,the results of assay systems for lipid peroxidation and sodium pump revealed that DPDS inhibited Na^(+)/K^(+)-ATPase and lipid peroxidation in the brain tissue homogenates in the same reaction system.A similar result was obtained in the assay system for lipid peroxidation and hepaticδ-ALAD as DPDS simultaneously inhibited the enzyme’s activity and lipid peroxidation.This suggests that the GPx mimetic property of DPDS may be linked to the enzymes’loss of activity,which further validates the suggestions that the enzymes’inhibition,as well as the antioxidant action of DPDS,rely on the oxidation of critical thiols of the enzymes.However,the GPx mimicry of DPDS should be investigated in the presence of thiol-blocking or oxidizing agents in biological systems in order to further ascertain the role of protein thiols. 展开更多
关键词 Organoseleniums diphenyl diselenide Glutathione peroxidase ANTIOXIDANT THIOLS delta-aminolevulinic acid dehydratase Na^(+)/K^(+)-ATPase
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Evaluation of Glutathione Peroxidase Enzymatic Activity in Seminal Plasma of Patients Treated at the Institute Pasteur in Cote d’Ivoire
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作者 Marie Florence N’Guessan Bi Bali Sery +4 位作者 Foua Jonas Vanié Bi N’Gbesso Amos Ekissi Youzan Ferdinand Djohan Founzégué Amadou Coulibaly Allico Joseph Djaman 《Advances in Reproductive Sciences》 2023年第4期116-126,共11页
Glutathione peroxidase (GPx) is an antioxidant that plays an important role in the maintenance of male fertility. The aim of this study was to compare the profile of enzymatic activity of glutathione peroxidase in the... Glutathione peroxidase (GPx) is an antioxidant that plays an important role in the maintenance of male fertility. The aim of this study was to compare the profile of enzymatic activity of glutathione peroxidase in the seminal plasma of normozoosperm and those of pathological sperm. Thus, the activity of glutathione peroxidase was determined in the seminal plasma of 20 normozoosperms, 9 azoosperms and 31 oligoasthenoteratozoosperms. It was 37.58 ± 3.14 U/L in normozoosperms, 39.39 ± 2.27 U/L in oligoasthenoteratozoosperms, and 29.77 ± 2.62 U/L in azoosperms. The mean GPx enzyme activity of normozoosperms did not differ significantly from that of oligoasthenoteratozoosperms and azoosperms. In contrast, comparison of enzyme activity between abnormal sperms gave a significant difference. This study showed that glutathione peroxidase enzymatic activity is not related to sperm quality. 展开更多
关键词 Glutathione peroxidase ANTIOXIDANT OLIGOASTHENOTERATOZOOSPERMIA AZOOSPERMIA Normozoospermia
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Effects of Hg^(2+) on Isozymes of Peroxidase,Catalase and Superoxide Dismutase in Wheat Seedlings 被引量:20
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作者 王琳 王林嵩 +4 位作者 王丽 孙向东 宗秀征 李芳军 高雅 《Agricultural Science & Technology》 CAS 2008年第5期19-23,共5页
[Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedl... [Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedlings under Hg2+ stress at different concentrations.[Result]① There were no obvious effects on the growth of seedlings when the concentration of Hg2+ was lower than 0.10 mmol/L.However,toxic effects on the growth of seedling were observed when the concentration of Hg2+ was higher than 0.10 mmol/L.② Different tissues showed different resistant ability in response to Hg2+ stress.The leaves and roots of wheat seedlings were more insensitive to Hg2+ toxicity.③ CAT was more sensitive to Hg2+ stress compared to POD and SOD.[Conclusion]The toxic effect was related to the concentration of Hg2+(0.10 mmol/L).The higher concentration of Hg2+ could affect the expression of POD,CAT,and SOD isozymes in the leaves,roots of wheat seedlings and germinated seeds,which further affect the normal metabolism of membrane lipid and inhibit the growth of wheat seedlings at last. 展开更多
关键词 Wheat Hg2+ stress peroxidase CATALASE Superoxide DISMUTASE ISOZYME
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Effects of Catalase and Ascorbate Peroxidase on the Root Growth of Rice under Cadmium Stress 被引量:9
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作者 宋新华 王凯 +1 位作者 郭蕾蕾 赵凤云 《Agricultural Science & Technology》 CAS 2011年第9期1256-1259,共4页
[Objective] The research aimed to study the correlations between catalase(CAT) and ascorbate peroxidase(ASP) and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua ... [Objective] The research aimed to study the correlations between catalase(CAT) and ascorbate peroxidase(ASP) and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua No.11 as materials,the changes of rice seedlings under the treatment conditions of Cd,Cd+CAT inhibitor,Cd+APX inhibitor were studied.[Result] Under Cd stress,inhibition of CAT activity caused the significant inhibition on the growth of aerial parts,decreased the number of adventitious roots and lateral roots,but it can significant promote the elongation growth of adventitious roots and lateral roots.Moreover,the length of the first lateral root from root tip on the primary roots and adventitious roots was also increased than control.When APX activity was inhibited,the growth changes of rice were similar with that treated by CAT inhibitor.[Conclusion] CAT and APX may play important roles in the regulation of rice root system growth in both non-stress and Cd-stressed rice 展开更多
关键词 Cd stress CATALASE Ascorbate peroxidase
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Regulation of Heat Shock Factor AtHsfA1a on Ascorbate Peroxidase under Heat Stress in Arabidopsis thaliana 被引量:1
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作者 郭丽红 谭越 杨晓虹 《Agricultural Science & Technology》 CAS 2016年第8期1786-1789,共4页
[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic ... [Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic A. thaliana with silenced endogenetic AtHsfA1a gene and wild A. thaliana plants as materials, the change in activity of APX enzyme was analyzed by spectrophotometry, the expression level of APX gene was investigated by real-time fluorescent quantitative PCR, and the binding condition of AtHsfAla with the promoter region of APX gene was analyzed by chromatin immunoprecipitation assay. [Result] The activity and mRNA level of APX in plants with silenced endogenetic AtHsfAla gene were higher than those in wild plants. Fragments of the promoter region of APX gene were not screened from the plants with silenced endogenetic AtHsfA1a gene, but found in wild plants. [Conclusion] This study provides a theoretical basis for the understanding of the important role of AtHsfAla in resistance to stress in plant, and is of great significance to the revealing of mechanism of resistance to stress in plant. 展开更多
关键词 Arabidopsis thaliana Heat shock factor AtHsfAla Aascorbate peroxidase Heat stress
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Enhanced Fenton,photo-Fenton and peroxidase-like activity and stability over Fe_3O_4/g-C_3N_4 nanocomposites 被引量:8
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作者 Yanan Liu Anwu Xu 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第12期2110-2119,共10页
We prepared the Fe3O4/g‐C3N4nanoparticles(NPs)through a simple electrostatic self‐assembly method with a3:97weight ratio to investigate their Fenton,photo‐Fenton and oxidative functionalities besides photocatalytic... We prepared the Fe3O4/g‐C3N4nanoparticles(NPs)through a simple electrostatic self‐assembly method with a3:97weight ratio to investigate their Fenton,photo‐Fenton and oxidative functionalities besides photocatalytic functionality.We observed an improvement of the Fenton and photo‐Fenton activities of the Fe3O4/g‐C3N4nanocomposites.This improvement was attributed to efficient charge transfer between Fe3O4and g‐C3N4at the heterojunctions,inhibition of electron‐hole recombination,a high surface area,and stabilization of Fe3O4against leaching by the hydrophobic g‐C3N4.The obtained NPs showed a higher degradation potential for rhodamine B(RhB)dye than those of Fe3O4and g‐C3N4.As compared to photocatalysis,the efficiency of RhB degradation in the Fenton and photo‐Fenton reactions was increased by20%and90%,respectively.Additionally,the horseradish peroxidase(HRP)activity of the prepared nanomaterials was studied with3,3,5,5‐tetramethylbenzidinedihydrochloride(TMB)as a substrate.Dopamine oxidation was also examined.Results indicate that Fe3O4/g‐C3N4nanocomposites offers more efficient degradation of RhB dye in a photo‐Fenton system compared with regular photocatalytic degradation,which requires a long time.Our study also confirmed that Fe3O4/g‐C3N4nanocomposites can be used as a potential material for mimicking HRP owing to its high affinity for TMB.These findings suggest good potential for applications in biosensing and as a catalyst in oxidation reactions. 展开更多
关键词 Fe3O4/g‐C3N4 nanocomposites Fenton reaction Dye degradation peroxidase activity Horseradish peroxidase mimicking Dopamine oxidation
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Effect of Lanthanum Ion on Peroxidase in Plant 被引量:1
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作者 姜慧君 王小锋 +3 位作者 周青 黄晓华 陆天虹 公衍道 《Journal of Rare Earths》 SCIE EI CAS CSCD 2002年第5期547-552,共6页
The interaction of MP 11 as a model of antioxidatase enzymes with La 3+ was investigated. It was found that La 3+ can increase in the non planarity of heme and the content of α helix and β turn conformat... The interaction of MP 11 as a model of antioxidatase enzymes with La 3+ was investigated. It was found that La 3+ can increase in the non planarity of heme and the content of α helix and β turn conformations of the MP 11 molecule. The change in the secondary structure of the MP 11 molecule can increase in the exposure extent of heme to the solution. Therefore, the electrochemical reaction of MP 11 is promoted and the electrocatalytic activity to the reduction of H 2O 2 is increased. The results are consistent with that for the interaction of peroxidases(POD), one of the antioxidatase enzymes, obtained in the living plant experiments at low concentration of La 3+ . 展开更多
关键词 rare earths lanthamum ion microperoxidase 11 peroxidase INTERACTION
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Detection mechanism and classification of design principles of peroxidase mimic based colorimetric sensors: A brief overview 被引量:1
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作者 Ali Reza Hormozi Jangi Mohammad Reza Hormozi Jangi Saeed Reza Hormozi Jangi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第6期1492-1503,共12页
Synthesis and characterization of enzyme mimics with characteristic stability and high catalytic efficiency is an interesting field for researchers.Especially,with the development of nanoscience and introducing of Fe3... Synthesis and characterization of enzyme mimics with characteristic stability and high catalytic efficiency is an interesting field for researchers.Especially,with the development of nanoscience and introducing of Fe3O4 magnetic nanoparticles as peroxidase mimics in 2007,various nanomaterials such as noble metals,metal oxides,and carbon materials were introduced as enzyme mimics(nanozymes).Various nanomaterials exhibit peroxidaselike activity,hence,most of the nanozymes are peroxidase mimetics.Although the nanozyme based sensors were previously classified,the classifications have been focused on the type of nanozyme action.Therefore,the nanozyme based sensors were classified as peroxidase,hydrolase,and urease mimic-based sensors.However,heretofore,these sensors are not classified based on the detection mechanism and principles of system design.The aim of this review is the focus on the peroxidase mimic based colorimetric sensors as the most common nanozyme-based sensors and their classification based on principles of sensor design and review of the detection mechanism of the current mimic peroxidase based sensors.Moreover,some current challenges and future developments in this field are discussed. 展开更多
关键词 peroxidase mimic Nanozyme Enzyme-peroxidase mimic hybrids HP sensing pH sensing Enzyme co-embedded nanomaterials
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Effects of low molecular weight heparin-superoxide dismutase conjugate on serum levels of nitric oxide,glutathione peroxidase,and myeloperoxidase in a gerbil model of cerebral ischemia/reperfusion injury
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作者 Qingde Wang Guixiang Cui +2 位作者 Hongxia Liu Yizhao Li Fengshan Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第11期1233-1236,共4页
BACKGROUND: Several studies have demonstrated that low molecular weight heparin-superoxide dismutase (LMWH-SOD) conjugate may exhibit good neuroprotective effects on cerebral ischemia/reperfusion injury though anti... BACKGROUND: Several studies have demonstrated that low molecular weight heparin-superoxide dismutase (LMWH-SOD) conjugate may exhibit good neuroprotective effects on cerebral ischemia/reperfusion injury though anticoagulation, decreasing blood viscosity, having anti-inflammatory activity, and scavenging oxygen free radicals. OBJECTIVE: To investigate the intervention effects of LMWH-SOD conjugate on serum levels of nitric oxide (NO), glutathione peroxidase (GSH-Px), and myeloperoxidase (MPO) following cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING: A randomized, controlled, and neurobiochemical experiment was performed at the Institute of Biochemical Pharmacy, School of Pharmaceutical Sciences, Shandong University between April and July 2004. MATERIALS: A total of 60 Mongolian gerbils of either gender were included in this study. Total cerebral ischemia/reperfusion injury was induced in 50 gerbils by occluding bilateral common carotid arteries. The remaining 10 gerbils received a sham-operation (sham-operated group). Kits of SOD, NO, and MPO were sourced from Nanjing Jiancheng Bioengineering Institute, China. LMWH, SOD, and LMWH-SOD conjugates were provided by Institute of Biochemistry and Biotechnique, Shandong University, China. METHODS: Fifty successful gerbil models of total cerebral ischemia/reperfusion injury were evenly randomized to five groups: physiological saline, LMWH-SOD, SOD, LMWH + SOD, and LMWH. At 2 minutes prior to ischemia, 0.5 mL/65 g physiological saline, 20 000 U/kg LMWH-SOD conjugate, 20 000 U/kg SOD, a mixture of SOD (20 000 U/kg) and LMWH (LMWH dose calculated according to weight ratio, LMWH: SOD = 23.6:51), and LMWH (dose as in the LMWH + SOD group) were administered through the femoral artery in each above-mentioned group, respectively. MAIN OUTCOME MEASURES: Serum levels of NO, MPO, and GSH-Px. RESULTS: Compared with 10 sham-operated gerbils, the cerebral ischemia/reperfusion injury gerbils exhibited decreased serum levels of GSH-Px and increased serum levels of NO and MPO (P 〈 0.01). The serum level of GSH-Px was significantly upregulated in all groups, in particular in the LMWH-SOD group (P 〈 0.01), compared with the physiological saline group (P 〈 0.05-0.01). Following medical treatment, serum levels of NO and MPO were significantly downregulated in all groups, in particular in the LMWH-SOD group (P 〈 0.01). Serum levels of GSH-Px, NO, and MPO in the LMWH-SOD group were close to those in the sham-operated group (P 〉 0.05). CONCLUSION: In cerebral ischemia/reperfusion injury, LMWH-SOD conjugate exhibits stronger neuroprotective effects on free radical scavenging, inflammation inhibition, and cytotoxicity inhibition than simple or combined application of LMWH and SOD by downregulating NO and MPO levels and upregulating the GSH-Px level. 展开更多
关键词 cerebral ischemia/reperfusion nitric oxide MYELOperoxidase glutathione peroxidase low molecular weight heparin-superoxide dismutase conjugate
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Microscopic Characteristics, Chromatographic Profiles and Inhibition of Peroxidase Activity of the Leaves of <i>Manihot esculenta</i>and <i>Manihot glaziovii</i>, Consumed as Traditional Vegetables
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作者 Paulin Mutwale Kapepula Patricia Mbombo Mungitshi +7 位作者 Dieudonné Tshitenge Tshitenge Thierry Franck Dieudonné Mumba Ngoyi Pascal Dibungi T. Kalenda Monique Tits Michel Frédérich Nadege Kabamba Ngombe Ange Mouithys-Mickalad 《Journal of Biosciences and Medicines》 2021年第9期59-73,共15页
Methanolic extracts from the leaves of <em>Manihot esculenta </em>(Two cultivars) and <em>Manihot glaziovii</em>, consumed as traditional vegetables in DR. Congo was chemically characterized by... Methanolic extracts from the leaves of <em>Manihot esculenta </em>(Two cultivars) and <em>Manihot glaziovii</em>, consumed as traditional vegetables in DR. Congo was chemically characterized by Thin layer Chromatography and High Performance Liquid Chromatography. <em>In vitro</em> biochemical activities of extracts against Radical Oxidative Species (ROS) production were assessed in cellular models, on enzymes, Myeloperoxidase (MPO) and Horseradish Peroxidase (HRP) involved in inflammation. The microscopic analysis of the powder of leaves showed that each species displays specific and discriminating botanical microscopic features. Varieties of<em> M. esculenta</em> had a chemical fingerprint different from <em>M. glaziovii</em>. The majority of compounds were polyphenols, represented mainly by rutin, kaempferol-3-O-rutinoside, amentoflavone, phenolic acids such as gallic acid. All extracts exhibited high cellular antioxidant activity in the range of 0.1 to 10 μg<span style="white-space:nowrap;">·</span>mL<sup>-1</sup> using lucigenin with neutrophils, but a moderate cellular antioxidant activity ranging between 10 and 100 μg<span style="white-space:nowrap;">·</span>mL<sup>-1</sup> with DCFDA on HL60 monocytes. Extracts from <em>Manihot</em> leaves showed a pronounced inhibitory effect on the production of extracellular ROS, on HRP and myeloperoxidase activity. Cellular antioxidant activities, the inhibitory effect on HRP of extracts from <em>M. glaziovii</em>, <em>M. esculenta</em> cultivar <em>Mwambu </em>were significantly higher, but their inhibitory effect on the activity of MPO was lower than those of <em>M. esculenta</em> cultivar TEM 419. The biological activities of <em>Manihot esculenta</em> and <em>Manihot glaziovii </em>were well correlated to their phytochemicals that could justify their traditional use as vegetables, potential functional foods or nutraceutical resources and medicines. 展开更多
关键词 Horseradish peroxidase Kahemba Konzo Manihot esculenta Manihot glaziovii MYELOperoxidase Traditional Vegetable
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Polyphenol Oxidase, Peroxidase and PhenylalanineAmmonium Lyase Induced in Postharvest Peach Fruitsby Inoculation with Pichia membranefaciensor Rhizopus stolonifer 被引量:13
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作者 QIN Guo-zheng, TIAN Shi-ping, LIU Hai-bo and XU Yong(Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany , Chinese Academy of Sciences , Beijing 100093 , P. R. China) 《Agricultural Sciences in China》 CAS CSCD 2002年第12期1370-1375,共6页
Rhizopus rot of peach fruits could be significantly suppressed by Pichia membranefaciens. Polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonium-lyase (PAL) activities induced by inoculation with P. mem... Rhizopus rot of peach fruits could be significantly suppressed by Pichia membranefaciens. Polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonium-lyase (PAL) activities induced by inoculation with P. membrane faciens or R. stolonifer were studied in postharvest peach fruits. The activities of PPO and PAL in peaches increased significantly after being inoculated with P. membrane faciens + R. stolonifer by 24 h, the activities maintained at a high level throughout the experiment. Under the condition of infected with R. stolonifer alone, activity of PPO and PAL could also increased, but the levels were lower than those treated with P. membrane faciens+ R. stolonifer. However, fruits inoculaed with P. membrane-faciens + R. stolonifer or R. stolonifer alone did not stimulated POD activity. The results suggest that the activation of these defense enzymes is involved in the action of P. membrane faciens against R. stolonifer. 展开更多
关键词 Peach fruits Polyphenol oxidase peroxidase Phenylalanine ammonium-lyase Pichia membranefaciens Rhizopus stolonifer
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Revealing the Intrinsic Peroxidase-Like Catalytic Mechanism of Heterogeneous Single-Atom Co-MoS2 被引量:8
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作者 Ying Wang Kun Qi +9 位作者 Shansheng Yu Guangri Jia Zhiliang Cheng Lirong Zheng Qiong Wu Qiaoliang Bao Qingqing Wang Jingxiang Zhao Xiaoqiang Cui Weitao Zheng 《Nano-Micro Letters》 SCIE EI CAS CSCD 2019年第4期778-790,共13页
The single-atom nanozyme is a new concept and has tremendous prospects to become a next-generation nanozyme.However,few studies have been carried out to elucidate the intrinsic mechanisms for both the single atoms and... The single-atom nanozyme is a new concept and has tremendous prospects to become a next-generation nanozyme.However,few studies have been carried out to elucidate the intrinsic mechanisms for both the single atoms and the supports in single-atom nanozymes.Herein,the heterogeneous single-atom Co-MoS2(SA Co-MoS2)is demonstrated to have excellent potential as a high-performance peroxidase mimic.Because of the well-defined structure of SA Co-MoS2,its peroxidase-like mechanism is extensively interpreted through experimental and theoretical studies.Due to the different adsorption energies of substrates on different parts of SA Co-MoS2 in the peroxidase-like reaction,SA Co favors electron transfer mechanisms,while MoS2 relies on Fenton-like reactions.The different catalytic pathways provide an intrinsic understanding of the remarkable performance of SA Co-MoS2.The present study not only develops a new kind of single-atom catalyst(SAC)as an elegant platform for understanding the enzyme-like activities of heterogeneous nanomaterials but also facilitates the novel application of SACs in biocatalysis. 展开更多
关键词 BIOCATALYSIS Nanozymes peroxidase MIMIC Reaction mechanisms SINGLE-ATOM catalysts
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Mechanisms of Salt Tolerance in Transgenic Arabidopsis thaliana Carrying a Peroxisomal Ascorbate Peroxidase Gene from Barley 被引量:9
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作者 XU Wei-Feng SHI Wei-Ming +1 位作者 A. UEDA T. TAKABE 《Pedosphere》 SCIE CAS CSCD 2008年第4期486-495,共10页
Ascorbate peroxidases (APX), localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H2O2 to water by using ascorbic acid as the specific electron donor. To det... Ascorbate peroxidases (APX), localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H2O2 to water by using ascorbic acid as the specific electron donor. To determine the role of peroxisomal type ascorbate peroxidase (pAPX), an antioxidant enzyme, in protection against salt-induced oxidative stress, transgenic Arabidopsis thaliana plant carrying a pAPX gene (HvAPX1) from barley (Hordeum vulgate L.) was analyzed. The transgenic line pAPX3 was found to be more tolerant to salt stress than the wild type. Irrespective of salt stress, there were no significant differences in Na^+, K^+, Ca^2+, and Mg^2+ contents and the ratio of K^+ to Na^+ between pAPX3 and the wild type. Clearly, the salt tolerance in pAPX3 was not due to the maintenance and reestablishment of cellular ion homeostasis. However, the degree of H2O2 and lipid peroxidation (measured as the levels of malondialdehyde) accumulation under salt stress was higher in the wild type than in pAPX3. The mechanism of salt tolerance in transgenic pAPX3 can thus be explained by reduction of oxidative stress injury. Under all conditions tested, activities of superoxide, glutathione reductase, and catalase were not significantly different between pAPX3 and the wild type. In contrast, the activity of APX was significantly higher in the transgenic plant than in wild type under salt stress. These results suggested that in higher plants, HvAPX1 played an important role in salt tolerance and was a candidate gene for developing salttolerant crop plants. 展开更多
关键词 ascorbate peroxidase oxidative stress PEROXISOME soil salinity transgenic Arabidopsis thaliana
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Studies on Manganese Peroxidase Immobilized in Gelatin-containing Microemulsion-based Gels 被引量:7
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作者 SONGShao-fang LUANYu-xia SUXiu-rong 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2005年第4期423-425,共3页
The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the M... The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn 2+ and H_2O_2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H_2O_2. When the amount of the immobilized H_2O_2 is sufficient, the microemulsion-based gels containing MnP could be used many times. 展开更多
关键词 Manganese peroxidase Microemulsion-based gel Immobilized enzyme Lignin model compound Syringaldazine
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Purification and Characterization of a Versatile Peroxidase from Edible Mushroom Pleurotus eryngii 被引量:8
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作者 陈敏 姚善泾 +1 位作者 张虹 梁新乐 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第5期824-829,共6页
A versatile peroxidase (VP-Peco60-7 ) was generated and purified from the liquid culture of Pleurotus eryngii. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, and gel c... A versatile peroxidase (VP-Peco60-7 ) was generated and purified from the liquid culture of Pleurotus eryngii. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, and gel chromatography. The molecular weight and isoelectric point (pI) of VP-Peco60-7 were determined to be approxi-mately 40 kDa and 4.1, respectively. By N-terminal sequence determination and peptide mapping analysis, VP-Peco60-7 was found to be similar to the versatile peroxidase isoenzyme VPL1, which was previously isolated from liquid cultures of the same species. However, the molecular weight and pI of VP-Peco60-7 were different from those of versatile peroxidases of liquid cultures, implying that the VP-Peco60-7 in this study is of a novel type. With 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a substrate, the maximal enzyme activity was obtained at 50 °C and pH 3.0. The catalysis of ABTS by VP-Peco60-7 was expressed by the Michaelis-Menten equa-tion. At 50 °C and pH 3.0, the maximum velocity (V max ) was 188.68 U·mg-1 and the michaelis constant (K m ) was 203.09 μmol·L-1 . 展开更多
关键词 Pleurotus eryngii versatile peroxidase PURIFICATION enzymatic properties
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Enhancement of Phenylalanine Ammonia Lyase,Polyphenoloxidase,and Peroxidase in Cucumber Seedlings by Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae) Infestation 被引量:8
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作者 ZHANG Shi-ze ZHANG Fan HUA Bao-zhen 《Agricultural Sciences in China》 CAS CSCD 2008年第1期82-87,共6页
In this study, the activities of phenylalanine ammonia lyase (PAL), polyphenoloxidase (PPO), and peroxidase (POD) were assayed in cucumber seedlings (Cucumis sativus L.) at 0, 6, 12, 24, 48, 72, and 96 h after... In this study, the activities of phenylalanine ammonia lyase (PAL), polyphenoloxidase (PPO), and peroxidase (POD) were assayed in cucumber seedlings (Cucumis sativus L.) at 0, 6, 12, 24, 48, 72, and 96 h after they were infested by Bemisia tabaci (Gennadius) using spectrophotometric analysis. The results indicated that herbivore infestation increased the activities of PAL, PPO, and POD. The enzymes showed different activity levels at different times after the infestation. The PAL activity reached the first high peak by 23.1% at 6 h and the highest peak by 29.1% at 48 h compared to the control. The PPO activity reached the first high peak by 22.7% at 6 h and the highest peak by 52.6% at 24 h, and the POD activity reached the highest peak by 213.2% at 6 h and another higher peak value by 135.2% at 96 h. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of cucumber plants against B. tabaci infestation. 展开更多
关键词 phenylalanine ammonia lyase POLYPHENOLOXIDASE peroxidase Bemisia tabaci induce response
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Cloning of catalase and expression patterns of catalase and selenium-dependent glutathione peroxidase from Exopalaemon carinicauda in response to low salinity stress 被引量:6
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作者 REN Hai LI Jian +4 位作者 LI Jitao YING Yu GE Hongxing LI Dongli YU Tianji 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第8期52-61,共10页
Catalase (CAT) and selenium-dependent glutathione peroxidase (Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H202, The objective of this paper is to evaluate th... Catalase (CAT) and selenium-dependent glutathione peroxidase (Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H202, The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawn Exopalaemon carinicauda in response to low salinity stress. A complementary DNA (cDNA) containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends. The full-length cDNA of CAT (2 649 bp) contains a 5'-untranslated region (UTR) of 78 bp, a 3'- UTR of 1 017 bp, with a poly (A) tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature (60FDRERIPERWHAKGAG76), proximal heme-ligand signature sequence (350RLFSYPDTH358) and three catalytic amino acid residues (His71, Asn144 and Tyr354). Sequence comparison showed that the CAT deduced amino acid sequence of E. carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT mRNA was widely expressed in the hepatopancreas (highest), hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress, CAT and GPx mRNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response in E. carinicauda. All these results indicate that E. carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress. 展开更多
关键词 Exopalaemon carinicauda catalase (CAT) selenium-dependent glutathione peroxidase (Se-GPx) CLONING expression
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Imaging of Activity of Horseradish Peroxidase at β-Cyclodextrin Polymer by Scanning Electrochemical Microscopy 被引量:13
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作者 XiaoLeiWANG YongXiangSHI +1 位作者 ZengLiangBAI WenRuiJIN 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第2期214-215,共2页
The activity of horseradish peroxidase at b-cyclodextrin polymer was imaged by scanning electrochemical microscopy using 3, 3', 5, 5'-tetramethylbenzide and H2O2 as the substrates.
关键词 Scanning electrochemical microscopy horseradish peroxidase.
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