超氧化物歧化酶

本文就超氧化物歧化酶的种类、分布、结构、活性部位、催化机理、纯化、活力测定、理化特性等方面作了介绍,并叙述了它的研究动向和发展前景。     

Changes of urinary albumin and N-acetyl-beta-glucosaminidase in high altitude polycythemia at different altitudes and its mechanism

AIM:To study the changes of excretive amount of albumin(ALB), N-acetyl-beta-D-glucosaminidase(NAG) in patients with high altitude polycythemia(HAPC) at different altitude and its mechanism.METHODS:Urinary ALB, NAG, activity of red blood cell superoxide dismutase(RBC-SOD), malonyldialdehyde(MDA) and erythrocyte filtration index(EFI) of 231 healthy subjects and 86 patients with HAPC at different altitude were detected.RESULTS:Excretive amount of urinary ALB, NAG, and plasma MDA, EFI were higher, and RBC-SOD was lower in patients with HAPC than those in healthy subjects, the changes were significantly obvious, with increasing altitude. Urinary ALB and NAG were negatively correlates to EFI, and no correlated to the content of MDA and RBC-SOD.CONCLUSIONS:EFI exertes an independent influence on urinary ALB and NAG. The decrease in erythrocyte deformability caused by the increase of peroxidation of lipids might participate in the pathogenesis and progress of the increase of excretive amount of ALB and NAG in HAPC.     

Induction of an antioxidant enzyme system and other oxidative stress markers associated with compatible and incompatible interactions between chickpea (Cicer arietinum L.) and Fusarium oxysporum f. sp.ciceris

To ascertain if active oxygen species play a role in fusarium wilt of chickpea caused by Fusarium oxysporum f. sp. ciceris, the degree of lipid peroxidation (malondialdehyde formation) and the activity levels of diamine oxidase (DAO), an apoplastic H₂O₂-forming oxidase, and several antioxidant enzymes, namely ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), guaiacol-dependent peroxidase (GPX) and superoxide dismutase (SOD), were determined spectrophotometrically in roots and stems of ‘WR315’ (resistant) and ‘JG62’ (susceptible) chickpea cultivars inoculated with the highly virulent race 5 of the pathogen. Moreover, APX, CAT, GPX and SOD were also analysed in roots and stems by gel electrophoresis and activity staining; and the protein levels of APX and SOD in roots were determined by Western blotting. In roots, infection by the pathogen increased lipid peroxidation and CAT and SOD activities, although such responses occurred earlier in the incompatible compared with the compatible interactions. APX, GPX and GR activities were also increased in infected roots, but only in the compatible interaction. In stems, infection by the pathogen increased lipid peroxidation and APX, CAT, SOD and GPX activities only in the compatible interaction, and DAO activity only in the incompatible one. In general, electrophoregrams agreed with the activity levels determined spectrophotometrically and did not reveal any differences in isoenzyme patterns between cultivars or between infected and non-infected plants. Further, Western blots revealed an increase in the root protein levels of APX in the compatible interaction and in those of SOD in both compatible and incompatible interactions. In conclusion, whereas enhanced DAO activity in stems, and earlier increases in lipid peroxidation and CAT and SOD activities in roots, can be associated with resistance to fusarium wilt in chickpea, the induction of the latter three parameters in roots and stems along with that of APX, GR (only in roots) and GPX (only in stems) activities are rather more associated with the establishment of the compatible interaction.     

Differential levels of antioxidants in paraquat-resistant and -susceptible Erigeron canadensis biotypes in Korea

To characterize the biochemical differences in paraquat-resistant and -susceptible biotypes of Erigeron canadensis L. collected from Korea, we investigated the constitutive levels of various antioxidants such as antioxidant enzymes and low molecular weight antioxidants in leaves, as well as after paraquat treatment. The activities of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase were higher in the paraquat-resistant biotype than in the paraquat-susceptible biotype. Reduced ascorbic acid content was higher in the resistant biotype, but the content of reduced glutathione was higher in the susceptible biotype. These results indicate that one of the paraquat-resistant mechanisms in E. canadensis in the present study might be related to protecting the activities of antioxidant enzymes, such as superoxide dismutase, peroxidase ascorbate peroxidase, and catalase, as well as the contents of low molecular weight antioxidants such as ascorbate and glutathione.     

SUPEROXIDE DISMUTASE FAMILY GENES IN WATERMELON AND THEIR RESPONSES TO DIFFERENT ABIOTIC STRESSES

• A total of 8 SOD genes from watermelon were identified and bioinformatically analyzed. • The SOD proteins from watermelon and other different plant species can be classified into five groups consistent with their metal cofactors. • ClSOD genes exhibited distinctive tissue-specific and abiotic stress responsive expression patterns. Superoxide dismutase (SOD) is an important enzyme in the antioxidant system of plants and plays a vital role in stress responses by maintaining the dynamic balance of reactive oxygen species (ROS) concentrations. Genome-wide analysis of the SOD gene family in various plant species has been conducted but little is known about this gene family in watermelon (Citrullus lanatus). Here, eight SOD genes were identified in the watermelon genome and are designated ClCSD1-5, ClFSD1-2 and ClMSD according to their metal cofactors. Phylogenetic analysis shows that SOD proteins from various plant species can be classified into five groups and members in the same group possess the same metal cofactor and similar subcellular localizations. Expression analysis of the ClSOD genes indicates that they had tissue-specific expression patterns with high expression in different tissues including the leaves, flowers and fruit. In addition, the expression of ClSOD genes differed appreciably under salinity, drought and abscisic acid (ABA) treatments, indicating that they may be involved in ROS scavenging under different abiotic stresses via an ABA-dependent signaling pathway. These results lay the foundation for elucidating the function of ClSOD genes in stress tolerance and fruit development in watermelon.     

金针菇液体培养菌丝与子实体SOD特性比较研究

液体发酵培养菌丝体具有高效、高产、成本低的特点。因此 ,本文以液体培养金针菇菌丝及金针菇子实体为材料 ,对二者SOD含量及同工酶类型进行了比较 ,并对金针菇菌丝液体培养的特性作了进一步阐述 ,以期为开发利用金针菇菌丝中SOD资源打下一定基础     

Pb对匍匐翦股颖根系超氧化物歧化酶活性的影响

通过Pb离子浓度胁迫与处理时间两因素试验方案,利用甲基氮蓝四唑(NBT)光密度测定法测定了匍匐翦股颖(Agrotistolonifera)根系细胞内超氧化物歧化酶(SODs)活性,并用统计分析软件SPSS13.0中的GenearLinearModel模块,对试验数据进行了F测验,用LSD法对各水平间进行多重比较检验。结果表明,重金属Pb各处理浓度对SODs的影响均达到极显著水平,处理后SODs水平显著上升,到第4d时达到最高值,处理第3d与第4d之间未达显著水平,第1、2d与第3、4、5d之间达到极显著水平发现低浓度(<2.5mmol·L-1)Pb处理可促使根系细胞积极的防御策略,使细胞SODs水平持续增加;高浓度(>10.0mmol·L-1)处理使SODs活性在早期上升,第4d后SODs开始下降,其主要原因是Pb离子胁迫产生的超量自由基导致酶失活效应所致。     

日本大耳白兔抗氧化物酶活性增龄性变化研究

选择日本大耳白兔,按年龄分为幼年、青年、老年三组,分别测定动脉血血清SOD、MDA、GSH—px活性水平,以探讨日本大耳白兔抗氧化物酶活性增龄性变化。结果显示：随着年龄的增长,血清SOD活性在中年期以前是随增龄而增加,青年组显著高于幼年CR（P〈0．05,P〈0．01）,在中年期以后是随增龄而降低,老年组明显低于青年组（P〈0．05,P〈0．01）;血清MDA含量是随增龄而增加,老年组明显高于青年组和幼年组（P〈0．05,P〈0．01）,青年组明显高于幼年CR（P〈0．05）;血清GSH—px活性随增龄而降低,老年组显著低于青年组和幼年组（P〈0．01）,青年组显著低于幼年组（P〈0．05,P〈0．01）。机体在衰老过程中体内自由基生成增加。抗氧化物酶活性全面降低可能是加速机体衰老的原因之一。     

热变性法提纯蜂王浆中SOD的初步研究

测定了蜂王浆中超氧化物歧化酶（SOD）在60℃，65℃，70，75℃4个温度条件下热击后的酶活及蜂王浆在这4个温度条件下的蛋白质总含量，根据其比活（酶活／蛋白质含量）大小可知在70℃温度条件下热处理蜂王浆是提纯蜂王浆中SOD的最佳温度。