期刊文献+
共找到8,640篇文章
< 1 2 250 >
每页显示 20 50 100
细叶百合Catalase基因的克隆及表达分析
1
作者 宋煜 林文昊 +2 位作者 荆一博 董懿 金淑梅 《植物研究》 CAS CSCD 北大核心 2023年第5期756-767,共12页
为探究细叶百合(Lilium pumilum)Catalase(CAT)基因与耐盐碱胁迫的关系,从细叶百合鳞茎中成功克隆出LpCat基因。该基因的ORF区长度为1479 bp,编码492个氨基酸,对其进行序列比对和系统进化树分析,发现细叶百合Catalase蛋白与通江百合(L.s... 为探究细叶百合(Lilium pumilum)Catalase(CAT)基因与耐盐碱胁迫的关系,从细叶百合鳞茎中成功克隆出LpCat基因。该基因的ORF区长度为1479 bp,编码492个氨基酸,对其进行序列比对和系统进化树分析,发现细叶百合Catalase蛋白与通江百合(L.sargentiae)、菠萝(Ananas comosus)、油棕(Elaeis guineensis)等植物的Catalase蛋白亲缘关系较近。构建了pQE-LpCat原核表达载体,以1 mol·L^(-1)IPTG为诱导剂进行LpCat蛋白的体外诱导表达与纯化。在添加50 mmol·L^(-1)NaHCO_(3)胁迫下,携带PQE-LpCat蛋白的菌液生长浓度高于对照菌株。在1 mol·L^(-1)NaHCO_(3)、2.5 mol·L^(-1)H_(2)O_(2)胁迫下过表达LpCAT基因烟草(Nicotiana plumbaginifolia)植株与野生型相比,枯萎程度相对较低。通过净光合速率、气孔导度、胞间CO_(2)和蒸腾速率,H_(2)O_(2)含量,丙二醛(MDA)等生理指标检测说明过表达LpCat基因烟草植株比野生型烟草植株更耐盐碱。 展开更多
关键词 细叶百合 catalase基因 盐碱逆境
下载PDF
幽门螺杆菌Catalase基因的克隆、表达及其抗原性鉴定 被引量:6
2
作者 李妍 宁云山 +2 位作者 龙敏 董文其 李明 《细胞与分子免疫学杂志》 CAS CSCD 北大核心 2006年第4期440-442,446,共4页
目的:构建含人幽门螺杆菌(Hpylori,Hp)过氧化氢酶(catalase,KatA)编码基因的重组质粒,测定、分析其核酸序列,并在E.coli中表达,研究其抗原性。方法:应用PCR技术从HpDNA染色体中扩增KatA编码基因片段,将其T-A克隆和测序,并... 目的:构建含人幽门螺杆菌(Hpylori,Hp)过氧化氢酶(catalase,KatA)编码基因的重组质粒,测定、分析其核酸序列,并在E.coli中表达,研究其抗原性。方法:应用PCR技术从HpDNA染色体中扩增KatA编码基因片段,将其T-A克隆和测序,并与GenBank公布的其他Hp菌株的基因序列比较,再将目的基因插入至融合表达载体pGEX-4T-1中进行表达,用GST亲和层析对其进行纯化。纯化产物用于对29株小鼠抗Hp-全菌单克隆抗体(mAb)的鉴定及与Hp啊感染患者血清进行Western blot。结果:KatA基因全长为1 515 bp,并在GenBank上登录(No.DQ333889),与GenBank公布的其他Hp菌株的核酸的同源性为96%~97%,表达的KatA融合蛋白的相对分子质量(Mr)为85 000,29株小鼠抗Hp全菌mAb中有4株mAb是针对KatA的,表达产物可被Hp感染患者的血清特异性识别。结论:重组KatA具有较好的抗原性,为坳检测试剂和疫苗的研究奠定了基础。 展开更多
关键词 幽门螺杆菌 catalase 克隆 基因表达 抗原性
下载PDF
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
3
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
下载PDF
幽门杆菌Catalase/GST融合蛋白的表达、标签切除及鉴定 被引量:6
4
作者 姜茵 奚月 李妍 《生物技术通报》 CAS CSCD 北大核心 2012年第2期102-106,共5页
旨在利用GST融合基因表达系统表达幽门螺杆菌Catalase融合蛋白,并利用凝血酶切除GST标签。将重组质粒Catalase/pGEX-4T-1转化大肠杆菌BL21(DE3)感受态中,用IPTG进行诱导表达,菌体经反复冻融、溶菌酶裂解及超声破菌后,Catalase/GST融合... 旨在利用GST融合基因表达系统表达幽门螺杆菌Catalase融合蛋白,并利用凝血酶切除GST标签。将重组质粒Catalase/pGEX-4T-1转化大肠杆菌BL21(DE3)感受态中,用IPTG进行诱导表达,菌体经反复冻融、溶菌酶裂解及超声破菌后,Catalase/GST融合蛋白以部分可溶性的形式表达在上清中。采用谷胱甘肽琼脂糖树脂Glutathione Sepharose 4B对其进行纯化,得到Catalase/GST融合蛋白,再用凝血酶进行GST标签的切除,所得产物进行Western blotting鉴定。高效表达出Catalase/GST融合蛋白的相对分子质量约85 kD,凝血酶成功地切除了GST标签,Western blotting证实Catalase蛋白能被鼠抗Catalase单克隆抗体识别。 展开更多
关键词 幽门螺杆菌 catalase 融合表达 GST标签切除 纯化
下载PDF
Association of Catalase Genotype with Oxidative Stress in the Predication of Colorectal Cancer:Modification by Epidemiological Factors 被引量:2
5
作者 CHANG Dong HU Zhang Liang +5 位作者 ZHANG Lin ZHAO Ya Shuang MENG Qing Hui GUAN Qing Bai ZHOU Jin PAN Hong Zhi 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2012年第2期156-162,共7页
Objective This paper aims to assess the interaction between common variations in catalase(CAT) polymorphic gene and environmental factors for antioxidant defense enzyme in modulating individual susceptibility to col... Objective This paper aims to assess the interaction between common variations in catalase(CAT) polymorphic gene and environmental factors for antioxidant defense enzyme in modulating individual susceptibility to colorectal cancer(CRC).Methods A case-control study with 880 colorectal cancer cases and 848 controls was conducted to investigate whether variations in the catalase(CAT) gene,one of the genes involved in scavenging oxidative stress,influenced susceptibility to CRC.Results The interaction between life style and genotypes as well as with their effects on colorectal cancer was deduced from the present study.Significant difference(P=0.01) was identified in the distribution of CAT genotype between the colorectal cancer cases and the controls.The CRC cases had significantly lower mean activity than the controls(P〈0.01).Correlation analyses revealed statistically significant correlations between CAT activity and CAT genotype(P〈0.01).Conclusion The risk of CRC was associated with smoking,low vegetable consumption,high pork and poultry consumptions,and low or high BMI.This is the first study reporting an association of polymorphism CAT-21A〉T with colorectal cancer.Low CAT activity was associated with an increased risk of CRC;however,no evidence was found to support an association between CAT-21A〉T polymorphism and CRC risk. 展开更多
关键词 Colorectal cancer (CRC) Oxidative stress catalase (cat gene Epidemiological factors
下载PDF
玉米catalase-3基因克隆及低温表达研究 被引量:11
6
作者 刘汉梅 张怀渝 +1 位作者 谭振波 黄玉碧 《四川农业大学学报》 CSCD 2006年第3期272-275,共4页
应用RT-PCR技术,从玉米自交系承18经14℃冷锻炼处理的芽鞘中扩增出长1491 bp的Cat3全长cDNA。以pGEM-T Easy为载体,克隆了扩增片段,经酶切鉴定和DNA序列测定,确认为玉米Cat3基因。序列分析结果表明,该序列与GenBank中accession number:L... 应用RT-PCR技术,从玉米自交系承18经14℃冷锻炼处理的芽鞘中扩增出长1491 bp的Cat3全长cDNA。以pGEM-T Easy为载体,克隆了扩增片段,经酶切鉴定和DNA序列测定,确认为玉米Cat3基因。序列分析结果表明,该序列与GenBank中accession number:L05934的序列仅在两个核苷酸位点存在差异。同时采用Northern杂交方法对Cat3在不同低温处理的玉米芽鞘中的表达特性进行了研究,结果显示Cat3在经14℃冷锻炼处理的芽鞘中表达增强,表明该基因受低温的诱导表达,为玉米抗寒基因,对提高玉米的抗寒力起积极作用。 展开更多
关键词 玉米 过氧化氢酶3 RT—PCR 抗寒
下载PDF
丝瓜过氧化氢酶(Catalase,CAT)酶学特性的研究 被引量:2
7
作者 张前荣 庄尹宏 +5 位作者 温庆放 刘建汀 叶新如 陈敏氡 王彬 朱海生 《中国园艺文摘》 2017年第9期1-3,31,共4页
为研究丝瓜过氧化氢酶(Catalase,CAT)酶学特性,本研究应用分光光度计开展温度、pH、酶体积、反应底物浓度等对酶反应的影响,为丝瓜酶促褐变的研究提供基础。结果表明,CAT最适反应体系:以H_2O_2为底物,最适底物浓度为0.33 mol/L H_2O_2,K... 为研究丝瓜过氧化氢酶(Catalase,CAT)酶学特性,本研究应用分光光度计开展温度、pH、酶体积、反应底物浓度等对酶反应的影响,为丝瓜酶促褐变的研究提供基础。结果表明,CAT最适反应体系:以H_2O_2为底物,最适底物浓度为0.33 mol/L H_2O_2,Km值为0.1818 mol/L,最适温度为40℃,最适pH值为7.8,最适酶液体积为0.1 ml。 展开更多
关键词 丝瓜 cat 酶学特性
下载PDF
Catalase活性在PTL诱导MM凋亡不同敏感性中的作用研究
8
作者 王巍 肖建兵 +1 位作者 安达正晃 周晋 《哈尔滨医科大学学报》 CAS 北大核心 2009年第1期9-11,16,共4页
目的研究小白菊内酯(PTL)对多发性骨髓瘤细胞敏感性的不同及机制,为PTL的联合化疗策略提供理论依据。方法以多发性骨髓瘤细胞KMM-1、MM1S、NCI-H929、KMS-5为研究对象,利用DAPI检测细胞凋亡、Weston blot检测过氧化氢酶(Catalase)蛋白... 目的研究小白菊内酯(PTL)对多发性骨髓瘤细胞敏感性的不同及机制,为PTL的联合化疗策略提供理论依据。方法以多发性骨髓瘤细胞KMM-1、MM1S、NCI-H929、KMS-5为研究对象,利用DAPI检测细胞凋亡、Weston blot检测过氧化氢酶(Catalase)蛋白的表达、流式细胞仪检测活性氧水平、Catalase-520和GPX-340试剂盒检测Catalase和谷胱甘肽过氧化物酶活性。结果KMS-5、NCI-H929与KMM-1、MM1S对2.5μmol/L、5μmol/L PTL凋亡率具有显著差异性(P<0.01)。在PTL 2.5μmol/L时活性氧增高与药物作用时间关系中,KMM-1、MM1S与KMS-5、NCI-H929相比,峰值显著升高(P<0.01)。在MM1S和KMM-1细胞Catalase的表达水平、活性与NCI-H929,KMS-5相比明显降低,Catalase抑制剂3-氨基-1,2,4-三唑提高NCI-H929,KMS-5对PTL介导的细胞凋亡。结论Catalase活性是PTL敏感性的关键因素,与Catalase抑制剂药物合用可以提高PTL更有效的抗MM的作用。 展开更多
关键词 小白菊内酯 多发性骨髓瘤 过氧化氢酶 敏感性 凋亡
下载PDF
苯系物对仿刺参catalase基因表达及酶活性的影响 被引量:9
9
作者 高士博 王摆 +5 位作者 董颖 高杉 蒋经伟 孙红娟 殷旭旺 周遵春 《生态毒理学报》 CAS CSCD 北大核心 2015年第2期297-305,共9页
以仿刺参(Apostichopus japonicus)为受试生物,采用半静水式试验方法,设置3种不同浓度(1/5、1/25、1/125的96 h-LC50)的苯、甲苯、乙基苯、邻–二甲苯、间–二甲苯和对–二甲苯处理健康仿刺参,检测仿刺参过氧化氢酶(CAT)基因在呼... 以仿刺参(Apostichopus japonicus)为受试生物,采用半静水式试验方法,设置3种不同浓度(1/5、1/25、1/125的96 h-LC50)的苯、甲苯、乙基苯、邻–二甲苯、间–二甲苯和对–二甲苯处理健康仿刺参,检测仿刺参过氧化氢酶(CAT)基因在呼吸树、肠组织中的表达和酶活性变化情况。结果发现:在各苯系物处理组的仿刺参呼吸树和肠组织中,cat基因的转录表达变化显著;苯、甲苯、乙基苯、邻–二甲苯对呼吸树中CAT活性具有诱导作用,其中乙基苯的诱导倍数最高,为12.0~19.8倍;6种苯系物对肠组织中CAT活性具有抑制作用,抑制程度大小顺序为:邻–二甲苯〉乙基苯〉对–二甲苯〉甲苯〉间–二甲苯〉苯。表明苯系物对仿刺参呼吸树、肠具有氧化胁迫作用,可能造成2种组织的氧化损伤。相关性分析表明:苯系物处理后,仿刺参肠组织中cat m RNA相对表达倍数与CAT活性变化呈显著正相关;仿刺参肠和呼吸树中cat m RNA相对表达倍数变化呈显著正相关。以上结果为苯系物对仿刺参的生物毒性评价提供了基础数据。 展开更多
关键词 苯系物(BTEX) 仿刺参 氧化损伤 过氧化氢酶(cat) 呼吸树
下载PDF
Response of soil catalase activity to chromium contamination 被引量:22
10
作者 Zofia Stepniewska Agnieszka Wolińska Joanna Ziomek 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第8期1142-1147,共6页
The impact of chromium(Ⅲ) and (Ⅵ) forms on soil catalase activity was presented. The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from different depths were used in the experiment. The soil samples were ame... The impact of chromium(Ⅲ) and (Ⅵ) forms on soil catalase activity was presented. The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from different depths were used in the experiment. The soil samples were amended with solution of Cr(Ⅲ) using CrCl3, and with Cr(Ⅵ) using K2Cr2O7 in the concentration range from 0 to 20 mg/kg, whereas the samples without the addition of chromium served as control. Catalase activity was assayed by one of the commonly used spectrophotometric methods. As it was demonstrated in the experiment, both Cr(Ⅲ) and Cr(Ⅵ) have an ability to reduce soil catalase activity. A chromium dosage of 20 mg/kg caused the inhibition of catalase activity and the corresponding contamination levels ranged from 75% to 92% for Cr(Ⅲ) and 68% to 76% for Cr(Ⅵ), with relation to the control. Catalase activity reached maximum in the soil material from surface layers (0-25 cm), typically characterized by the highest content of organic matter creating favorable conditions for microorganisms. 展开更多
关键词 CHROMIUM catalase enzymatic activity INHIBITION
下载PDF
槟榔Catalase 基因的克隆及亚细胞定位 被引量:1
11
作者 梁婷 沈文涛 +4 位作者 庹德财 言普 黎小瑛 唐庆华 周鹏 《热带作物学报》 CSCD 北大核心 2020年第12期2372-2378,共7页
过氧化氢酶(Catalase)广泛存在于生物体内,主要功能是清除植物细胞内光呼吸、线粒体电子传递及脂肪β-氧化等过程中产生的H2O2,从而保护细胞免于过氧化氢酶的毒害。为了解槟榔过氧化氢酶基因的相关信息,利用植物总RNA提取试剂盒提取槟... 过氧化氢酶(Catalase)广泛存在于生物体内,主要功能是清除植物细胞内光呼吸、线粒体电子传递及脂肪β-氧化等过程中产生的H2O2,从而保护细胞免于过氧化氢酶的毒害。为了解槟榔过氧化氢酶基因的相关信息,利用植物总RNA提取试剂盒提取槟榔叶片总RNA,通过同源克隆和RACE技术获得槟榔全长cDNA,并对其进行生物信息学分析及亚细胞定位。结果表明:获得ArCAT1(MN692600)、ArCAT2(MN692601)、ArCAT3(MN692602)3个同源基因,其序列全长均为1476 bp,编码492个氨基酸。遗传进化分析显示,ArCATS与同为棕榈科的油棕(Elaeis guineensis)、海枣(Phoenix dactylifera)等植物的过氧化氢酶氨基酸序列具有较高的相似性,其中与油棕的亲缘关系最近。亚细胞定位结果表明,ArCAT1蛋白定位于过氧化物酶体中,而ArCAT2和ArCAT3既定位于过氧化物酶体又定位于细胞核中。这为进一步研究Catalase基因在槟榔中的生物学功能奠定基础。 展开更多
关键词 槟榔 过氧化氢酶 亚细胞定位 基因克隆
下载PDF
Modulatory effect of pineapple peel extract on lipid peroxidation,catalase activity and hepatic biomarker levels in blood plasma of alcoholinduced oxidative stressed rats 被引量:13
12
作者 Okafor OY Erukainure OL +3 位作者 Ajiboye JA Adejobi RO Owolabi FO Kosoko SB 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2011年第1期12-14,共3页
Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Meth... Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Methods:Oxidative stress was induced by oral administration of ethanol(20%w/v) at a dosage of 5 niL/kg bw in rats.After 28 days of treatment,the rats were fasted overnight and sacrificed by cervical dislocation.Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min.The plasma was analyzed to evaluate malondialdehyde(MDA),catalase activity,aspartate aminotransferase(AST),alkaline phosphatase(ALP) and alanine aminotransferase(ALT) concentrations.Results:Administration of alcohol caused a drastic increase(87.74%) in MDA level compared with the control.Pineapple peel extract significantly reduced the MDA level by 60.16%at 2.S mL/kg bw.Rats fed alcohol only had the highest catalase activity,treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity.Increased AST,ALP and ALT activities were observed in rats fed alcohol only respectively,treatment with pineapple peel extract drastically reduced their activities. Conclusions:The positive modulation of lipid peroxidation,catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcoholinduced oxidative stress is an indication of its protective ability in the management of alcoholinduced toxicity. 展开更多
关键词 Blood PLASMA catalase LIPID peroxide Aspartate AMINOTRANSFERASE Alkaline phosphatase Alanine AMINOTRANSFERASE HEPATIC BIOMARKER Pineapple peel EXTRACT Oxidative stress LIPID peroxidation
下载PDF
Response of Superoxide Dismutase,Catalase,and ATPase Activity in Bacteria Exposed to Acetamiprid 被引量:5
13
作者 XIAO-HUA YAO HANG MIN ZHEN-MEI LV 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2006年第4期309-314,共6页
Objective To investigate how acetamiprid, a new insecticide, affects the activity of superoxide dismutase (SOD), catalase (CAT), and ATPase and the SOD isozyme patterns in two G-bacteria, E. coli K12 anti Pse.FH2,... Objective To investigate how acetamiprid, a new insecticide, affects the activity of superoxide dismutase (SOD), catalase (CAT), and ATPase and the SOD isozyme patterns in two G-bacteria, E. coli K12 anti Pse.FH2, and one G^+ bactemm, B. subtilis. Methods The SOD, CAT, and ATPase specific activities of cell lysates were determined spectrophotometrically at 550 nm, 240 nm, and 660 nm, respectively, with kits A001, A016, and A007. SOD isozyme patterns were detected by native PAGE analysis. Results SOD and CAT activities in the tested bacteria increased significantly in a concentration-dependent manner after different concentrations of acetamiprid were applied. The activity of SOD in B. subtilis and Pse.FH2 was stimulated and reached the highest level after treatment with 100 mg/L acetamiprid for 0.5 h. For Pse.FH2, there was another stimulation of SOD activity after acetamiprid application for about 8.0 h and the second stimulation was stronger than the first. The stimulation by acetamiprid showed a relative lag for E. coli K12. Acetamiprid seemed to exhibit a similar effect on CAT activity of the two G bacteria and had an evident influence on ATPase activity in the three bacteria within a relatively short period. Only one SOD isozyme was detectable in Pse.FH2 and B. subtilis, while different isozyme compositions in E. coli could be detected by native PAGE analysis. Conclusion Acetamiprid causes a certain oxidative stress on the three bacteria which may not only elevate SOD and CAT activities but also generate new SOD isozymes to antagonize oxidative stress. However, this oxidative stress lasts for a relatively short time and does not cause a long-term damage. 展开更多
关键词 ACETAMIPRID SOD cat ATPASE Stress response Native PAGE
下载PDF
Molecular cloning, characterization and expression analysis of a catalase gene in Paphia textile 被引量:1
14
作者 WU Xiangwei LI Jiakai +1 位作者 TAN Jing LIU Xiande 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第8期65-73,共9页
Catalase is an important antioxidant protein that can protect organisms against various forms of oxidative damage by eliminating hydrogen peroxide. In this study, the catalase c DNA of Paphia textile(Pt CAT) was clo... Catalase is an important antioxidant protein that can protect organisms against various forms of oxidative damage by eliminating hydrogen peroxide. In this study, the catalase c DNA of Paphia textile(Pt CAT) was cloned using RTPCR and rapid amplification of c DNA ends(RACE). Pt CAT is 1 921 bp long and consists of a 5′-UTR of 50 bp, a 3′-UTR of 349 bp, and an ORF of 1 542 bp that encodes 513 amino acids with a molecular weight of 58.4 k D and an estimated isoelectric point of 8.2. Sequence alignment indicated that Pt CAT contained a highly conserved catalytic signature motif(^(61)FNRERIPERVVHAKGAG^(77)), a proximal heme-ligand signature sequence(^(352)RLFSYSDP^(359)), and three catalytic amino acid residues(H^(72), N^(145), and Y^(356)). Pt CAT also contains two putative N-glycosylation sites(^(34)NKT^(36) and ^(437)NFT^(439)) and a peroxisome-targeting signal(^(511)AQL^(513)). Furthermore, Pt CAT shares 53%–88% identity and 29%–89% similarity with other catalase amino acid sequences. Pt CAT m RNA was present in all tested organs, including the heart, digestive gland, adductor muscle, gonad, gill, and mantle, but its expression was highest in the digestive gland. High-temperature-induced stress produced two expression patterns of Pt CAT m RNA: first, an initial up-regulation followed by a down-regulation in the heart, digestive gland, and gonad and, second, consistent down-regulation in all other organs. These results demonstrate that Pt CAT is a typical member of the catalase family and might be involved in the responses to harmful environmental factors. 展开更多
关键词 Paphia textile catalase(cat cloning sequence analysis expression analysis high temperature stress
下载PDF
HIGHLY SENSITIVE CATALASE ELECTRODE BASED ON POLYPYRROLE FILMS WITH MICROCONTAINERS 被引量:1
15
作者 Yu-ying Gao Gao-quan Shi 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2006年第6期579-584,共6页
Highly sensitive catalase electrodes for sensing hydrogen peroxide have been fabricated based on polypyrrole films with microcontainers. The microcontainers have a cup-like morphology and are arranged in a density of ... Highly sensitive catalase electrodes for sensing hydrogen peroxide have been fabricated based on polypyrrole films with microcontainers. The microcontainers have a cup-like morphology and are arranged in a density of 4000 units cm^-2. Catalase was immobilized into the polypyrrole films with microcontainers (Ppy-mc), which were coated on a Pt substrate electrode. The catalase/Ppy-mc/Pt electrode showed linear response to hydrogen peroxide in the range of 0-18 mmol/L at a potential of-0.3 V (versus SCE). Its sensitivity was measured to be approximately 3.64 μA (mmol/L) ^-1 cm^- 2, which is about two times that of the electrode fabricated from a flat Ppy film (catalase/Ppy-flat/Pt electrode). The electrode is highly selective for hydrogen peroxide and its sensitivity is interfered by potential interferents such as ascorbic acid, urea and fructose. Furthermore, such catalase electrodes showed long-term storage stability of 15 days under dry conditions at 4℃. 展开更多
关键词 Microstructured polypyrrole catalase ELECTROPOLYMERIZATION SENSORS Hydrogen peroxide.
下载PDF
采用LTE Cat.1通信的物联网高精度高度计设计
16
作者 郑俊华 郑雅伟 《集成电路与嵌入式系统》 2024年第2期96-100,共5页
为解决传统的基于物联网的远程测量技术中存在的测量精度与传感器成本无法兼顾、数据更新实时性不好、通信成本过高的问题,提出一种传感器数据采集方案,利用软件算法实现了高精度。同时,采用LTE Cat 1为数据通信方式,将数据传输到远程... 为解决传统的基于物联网的远程测量技术中存在的测量精度与传感器成本无法兼顾、数据更新实时性不好、通信成本过高的问题,提出一种传感器数据采集方案,利用软件算法实现了高精度。同时,采用LTE Cat 1为数据通信方式,将数据传输到远程云服务器及终端。将方案运用到远程海拔高度测量中,经过严谨的计算和测试验证,测量的绝对误差小于5 m,相对误差低于0.5%,数据传输的稳定性高,实时性可以控制到1 s之内,同时兼顾了通信的成本,在数据上传频率达到1次/s的情况下,数据流量可以控制在600 KB/h,满足系统的高精度、低成本、高实时性和稳定性要求。 展开更多
关键词 物联网 传感器 远程测量 LTE cat.1
下载PDF
嵌入Cat映射的混合变异探路者算法及其应用 被引量:1
17
作者 毛雪迪 王冰 +2 位作者 夏煌智 张鲁平 李永超 《计算机技术与发展》 2024年第2期171-179,共9页
针对探路者算法(PFA)求解精度不高、寻优速度较慢与易陷入局部最优等问题,提出一种嵌入Cat映射的混合变异探路者算法(CHMPFA)运用于函数优化问题中。首先,利用Cat混沌映射的随机性和分散性等特点,再结合反向学习的引导作用,使种群能够... 针对探路者算法(PFA)求解精度不高、寻优速度较慢与易陷入局部最优等问题,提出一种嵌入Cat映射的混合变异探路者算法(CHMPFA)运用于函数优化问题中。首先,利用Cat混沌映射的随机性和分散性等特点,再结合反向学习的引导作用,使种群能够覆盖在更为广阔的搜索空间,提高算法的全局搜索能力;其次,在探路者位置更新阶段引入衰减因子平衡算法的全局和局部搜索能力,通过迭代次数的增长逐渐地缩小搜索空间范围,帮助算法快速找到最优解,从而提升算法的搜索效率和收敛速度;最后,利用变异概率随机选择柯西变异或高斯变异对最优个体进行位置扰动,两种变异策略能够帮助个体快速跳出局部最优向其它区域前进。将CHMPFA在10个经典基准测试函数和12个复杂的CEC2017函数集上进行测试,并将其运用于压力容器工程设计问题,与原算法和其它算法的实验结果进行比较,结果表明CHMPFA的求解精度、寻优速度与局部最优规避性均明显加强,更低的工程造价成本进一步验证了CHMPFA的鲁棒性。 展开更多
关键词 探路者算法 函数优化问题 cat映射 混合变异 工程优化问题
下载PDF
Glutathione peroxidase, superoxide dismutase and catalase activities in children with chronic hepatitis 被引量:2
18
作者 Nagwa Abdallah Ismail Sawsan H. Okasha +3 位作者 Anil Dhawan Azza M. O. Abdel Rahman Nehal Abdel Hamid Olfat Shaker 《Advances in Bioscience and Biotechnology》 2012年第7期972-977,共6页
The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severit... The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severity of hepatic injury. We aimed to study the oxidative stress state in children with chronic hepatitis by using indirect approach in which antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) are determined in the liver tissue. The present study included 21 children and adolescents (12 males, 9 females) suffering from chronic hepatitis. Patients were selected from the Hepatology Clinic, New Children’s Hospital, Cairo University from November 2006 till 2009 and compared with a group of 7 children who happened to have incidental normal liver biopsy. Children with chronic hepatitis had mean age 8.12 ± 1.15 years. It was further subdivided into 2 subgroups: chronic viral heaptitis (n = 13) and cryptogenic hepatitis (n = 8). GPX, SOD and CAT levels were measured in fresh liver tissue (cell free homogenates) using ELISA. In chronic hepatitis group;there was a significant increase in the hepatic GPX activity (38.59 ± 35.82 nmol/min/ml) as compared to the control group (10.62 ± 6.68 nmol/min/ml). Also a significant correlation was observed between SOD and both ALT (r = 0.87, p < 0.05) and AST (r = 0.74, p < 0.05). GPX correlated with ALT (r = 0.80, p < 0.05) level in the chronic viral hepatitis subgroup. Our findings suggest that oxidative stress could play a role in the pathogenesis of chronic hepatitis. These preliminary results are encouraging to conduct more extensive clinical studies combining antioxidant therapy with various treatments. 展开更多
关键词 GLUTATHIONE PEROXIDASE Superoxide DISMUTASE catalase Chronic HEPATITIS Oxidative Stress
下载PDF
Mailuoning suppresses H_2O_2-induced cortical neuronal injury and correlates with increased catalase activity and inhibited oxidative stress function 被引量:1
19
作者 Xiaofan Pan Siyuan Huang +1 位作者 Lingling Li Yun Xu 《Neural Regeneration Research》 SCIE CAS CSCD 2010年第8期611-617,共7页
BACKGROUND:Mailuoning, a Chinese herb, has been widely used in China to treat acute ischemic stroke, and the major component exhibits anti-oxidative effects. However, the precise anti-oxidation pathway remains uncert... BACKGROUND:Mailuoning, a Chinese herb, has been widely used in China to treat acute ischemic stroke, and the major component exhibits anti-oxidative effects. However, the precise anti-oxidation pathway remains uncertain.OBJECTIVE:To validate the protective effects of Mailuoning on H202-induced primary cortical neuron injury in embryonic mice.DESIGN, TIME AND SETTING:Comparative observation and in v#ro experiments were performed at the Jiangsu Key Laboratory for Molecular Medicine from January 2008 to September 2009.MATERIALS:Mailuoning (Nanjing Jinling Medical Company, China), reactive oxygen species (ROS) kit (Beyotime Biotechnology, China), superoxide dismutase (SOD), Cu/Zn SOD kit, malondialdehyde (MDA) kits (Nanjing Jiancheng, China), mitochondrial membrane potential (GMS10013.1, GENMED, USA) and catalase activity assay kit (Beyotime Biotechnology, China) were utilized for the present study.METHODS:Mouse embryonic cortical neurons were isolated and cultured with culture medium containing H2O2 (80 μmol/L) and/or Mailuoning (1.25 μg/mL) for 24 hours.MAIN OUTCOME MEASURES:Neuronal viability and death were detected by methyl thiazolyl tetrazdium and flow cytometry; ROS production was determined by flow cytometry; mitochondriai membrane potential was detected using fluorescent staining; SOD activity was detected using a modified nitroblue tetrazolium method; Cu/Zn SOD and catalase activity was detected by spectrophotometry; and MDA was determined using the lipid peroxidation method.RESULTS:H2O2 increased ROS production and MDA concentration (P 〈 0.05), and decreased mitochondrial membrane potential, SOD, Cu/Zn SOD and catalase activity (P 〈 0.05); the number of surviving neurons (P 〈 0.05) was also reduced. Mai/uoning reversed these changes.CONCLUSION:Mailuoning protects H2O2-induced injury in cortical cells by inhibiting ROS and MDA, increasing depolarization of mitochondrial membrane, and enhancing SOD and catalase activity. 展开更多
关键词 MAILUONING oxidative stress NEURONS reactive oxygen species catalase activity traditional Chinese medicine mice brain injury neural regeneration
下载PDF
Inflammation/bioenergetics-associated neurodegenerative pathologies and concomitant diseases:a role of mitochondria targeted catalase and xanthophylls 被引量:6
20
作者 Mikhail A.Filippov Olga G.Tatarnikova +1 位作者 Natalia V.Pozdnyakova Vasily V.Vorobyov 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第2期223-233,共11页
Various inflammatory stimuli are able to modify or even"re-program"the mitochondrial metabolism that results in generation of reactive oxygen species.In noncommunicable chronic diseases such as atheroscleros... Various inflammatory stimuli are able to modify or even"re-program"the mitochondrial metabolism that results in generation of reactive oxygen species.In noncommunicable chronic diseases such as atherosclerosis and other cardiovascular pathologies,type 2 diabetes and metabolic syndrome,these modifications become systemic and are characterized by chronic inflammation and,in particular,"neuroinflammation"in the central nervous system.The processes associated with chronic inflammation are frequently grouped into"vicious circles"which are able to stimulate each other constantly amplifying the pathological events.These circles are evidently observed in Alzheimer's disease,atherosclerosis,type 2 diabetes,metabolic syndrome and,possibly,other associated pathologies.Furthermore,chronic inflammation in peripheral tissues is frequently concomitant to Alzheimer's disease.This is supposedly associated with some common genetic polymorphisms,for example,Apolipoprotein-Eε4 allele carriers with Alzheimer's disease can also develop atherosclerosis.Notably,in the transgenic mice expressing the recombinant mitochondria targeted catalase,that removes hydrogen peroxide from mitochondria,demonstrates the significant pathology amelioration and health improvements.In addition,the beneficial effects of some natural products from the xanthophyll family,astaxanthin and fucoxanthin,which are able to target the reactive oxygen species at cellular or mitochondrial membranes,have been demonstrated in both animal and human studies.We propose that the normalization of mitochondrial functions could play a key role in the treatment of neurodegenerative disorders and other noncommunicable diseases associated with chronic inflammation in ageing.Furthermore,some prospective drugs based on mitochondria targeted catalase or xanthophylls could be used as an effective treatment of these pathologies,especially at early stages of their development. 展开更多
关键词 algae xanthophylls Alzheimer's disease atherosclerosis depression type 2 diabetes metabolic syndrome mitochondria-targeted catalase noncommunicable chronic diseases stress
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部