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大豆萌发过程的活性氧代谢 总被引:16,自引:0,他引:16
本文研究了大豆萌发过程中活性氧的产生与清除,并探讨了光因子在活性氧代谢中的作用。大豆呼吸强度、O产生速率及H2O2水平都在吸水后第四天达到高峰,然后下降,三者的变化趋势同步。SOD、POD及APX的活性随萌发过程而逐渐增强,最后趋于平稳。SOD同工酶谱中分别于萌发的第二、第三天各出现一条新的酶带。CAT在萌发的初期猛增50倍左右,之后趋于稳定。在三种清除H2O2的酶(CAT、POD、APX)中,CAT清除H2O2的能力远远高于POD与APX,CAT可能是大豆萌发过程中最主要的H2O2清除酶。光萌发时呼吸强度低于暗中萌发,但O产生速率与H2O2水平高于暗萌发,光萌发时O的产生占总耗氧量的1.1—2.7%,而暗中萌发为0.9—1.3%。光条件下SOD、APX活性明显高于暗中萌发,而POD与CAT则在光和暗条件下相差不大。 相似文献
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低温对植物叶片中超氧物歧化酶、过氧化氢酶和过氧化氢水平的影响 总被引:10,自引:0,他引:10
番茄和鸡蛋果叶片中可提取的SOD活性不受低温的影响。在电泳谱带上SOD主同工酶带被氰化物而不被低温抑制,次同工酶带在低温下不稳定,且活性很低,它的变化不影响总的SOD活性。一些冷敏感植物叶片中CAT活性被低温抑制,而H_2O_3水平在低温下稳定或有增加,这可能使毒性更强的羟基离子(OH·)易于形成。 相似文献
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GA_3和BR对离体苎麻叶片中过氧化氢酶和过氧化物酶的影响及其与超氧物歧化酶的关系(简报) 总被引:1,自引:0,他引:1
经1.0mg·L-1GA3和0.1mg·L-1BR分别处理后的离体苎麻叶圆片中,过氧化物酶和过氧化氢酶活性都有明显增加。过氧化物酶的最大增加值出现在12h;过氧化氢酶与超氧物歧化酶同步,最大增加值出现时间都在处理后36h。0.2mmol·L-1H202处理的过氧化氢酶和超氧物歧化酶活性都增加;3.0mg·L-1NaN3处理的超氧物歧化酶活性明显增加;19.5mg·L-1KCN处理的过氧化氢酶活性则明显下降。 相似文献
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本文以三聚氰氯为活化剂,采用聚乙二醇法对超氧化物歧化酶进行化学修饰,得到了均一的聚乙二醇-SOD加合物。修饰酶活力为天然酶的75%,表明酶活性中心结构基本保持。 对修饰酶残留氨基的测定表明,近80%可滴定氨基参加了反应,且SOD骨架结构在修饰前后变化不大,可以推测聚乙二醇是连结在蛋白质表面上的。 相似文献
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蛹虫草超氧化物歧化酶分离纯化及稳定性的研究 总被引:2,自引:0,他引:2
以蛹虫草为材料,经过硫酸铵盐析、Sephedex G-75柱层析和DEAE-52柱层析,得到纯化的超氧化物歧化酶(SOD),经聚丙烯酰胺凝胶电泳显示单一区带,此酶比活力为17855.73u/mg,纯化倍数为53.7,回收率为21.8%。同时鉴于SOD在溶液中容易失活,无法长期保存,该文研究了不同浓度的糖类及不同浓度的有机酸类对SOD活力的影响,发现糖类对SOD活力影响不明显,有机酸均使SOD活力下降,但随着酸浓度的增加,SOD活力下降的程度也减轻。 相似文献
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The enzymes of hydrogen peroxide metabolism have been investigated in the cestodes H. diminuta and M. expansa. Neither catalase, lipoxygenase, glutathione peroxidase, NADH peroxidase nor NADPH peroxidase could be detected in homogenates of either species. However, both H. diminuta and M. expansa possessed a peroxidase which had a high affinity for reduced cytochrome c. The peroxidase was characterized by substrate and inhibitor studies and cell fractionation showed the enzyme to be located in the mitochondrial membrane fraction. The peroxidase could act as a substitute for catalase, by destroying metabolic hydrogen peroxide. Appreciable superoxide dismutase activity was found in M. expansa and H. diminuta and it is possible that this enzyme is the source of helminth hydrogen peroxide. 相似文献
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《Free radical research》2013,47(1):851-858
As a consequence of their oxygen rich environment, organelles of photosynthetic tissues are exposed to large fluxes of oxyradicals and reactive oxygen species. Superoxide, hydrogen peroxide, hydroxyl radical and singlet oxygen are all potential by-products of respiratory and photosynthetic systems. Strong reduc-tants found in mitochondria and chloroplasts along with a steady flux of photosynthetically generated oxygen enhance the potential for oxyradical production. Unless ncturalized by scavenger substrates or enzymes, these reactive intermediates pose a lethal threat.The presence of superoxide dismutases, cdtalases. various peroxidases and scavenger substrates are all means of defences available to protect organelles. A balance between oxyradical production and neutralization should exist. Perturbations in generation or in sequestration caused by environmental or nutritional factors might profoundly alter the steady state level of oxyintermediates. 相似文献
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应用菜粉蝶颗粒体病毒单克隆抗体对不同株病毒进行抗原分析 总被引:1,自引:0,他引:1
应用杂交瘤技术,以大菜粉蝶颗粒体病毒(pbGV)、菜粉蝶颗粒体病毒北京分离株(prGV-801)、武汉分离株(prGVw1-78)和济南分离株(prGV-J)等4株病毒为抗原,获得9株杂交瘤细胞(Fr1~9)。ELISA测定细胞培养上清抗体效价最高达8000,腹水效价最高达450000。9株杂交瘤细胞所分泌的抗体,各呈现株或组特异性,其中pr1~4分别与4个毒株起反应,pr5~8可与2~3个毒株起反应,而Pr9则与所有4个毒株均起反应。据此,认为这4个毒株有抗原性差异。不同毒株间抗原性的差异不仅存在于病毒粒子上,而且也存在于颗粒体蛋白上。讨论了昆虫病毒单克隆抗体在鉴别病毒抗原性差异,生物防治和流行病学研究中的意义。 相似文献
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1978年3月,作者首先发现了菜白蝶的一种新病毒.其后对该病毒的分离、鉴定、病毒的生物物理性质、血清学性质以及病毒的核酸性质等进行了报道.以其主要特性证明,该病毒可能为细小病毒科、密核病毒属的一个新种.Kusetak曾报道细小病毒科的密核病毒属,其病毒易感染脊椎动物的多种细胞.菜白蝶的这种新病毒是否具有此特性,作者用地鼠肾细胞进行了感染试验,现将结果报道如下.1 材料和方法1.1病毒增殖取低温保藏的毒种,置于常温下进行温度平衡.然后将毒种悬液涂于新鲜洁净的甘蓝叶上,饲喂经饥饿处理的菜青虫,感染5天左右,收集典型症状病死的幼虫,用无菌水研磨均匀,4000g×离心30分钟,除去虫体碎片,上清液再次扩大饲喂幼虫,如此反复至病死幼虫够量. 相似文献
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Cristina Sgherri M. Teresa A. Milone Herman Clijsters Flavia Navari-Izzo 《Journal of plant physiology》2001,158(11):1439-1447
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外源精胺对小麦幼苗抗氧化酶活性的促进作用 总被引:6,自引:0,他引:6
外源精胺(Spm)降低了离体小麦叶片衰老时MDA的含量,且降低程度与精胺的浓度成正比。0.2mmol/L的精胺提高了小麦幼苗体内的超氧化物歧化酶(SOD),过氧化氢酶(CAT),过氧化物酶(POD)及抗坏血酸过氧化物酶(ASP)的活性。体内及体外试验表明精胺既可诱导SOD与POD的合成,又可直接作用于酶分子上以提高酶的活性;精胺对CAT合成仅能诱导,对已有酶活性无调节作用;精胺对ASP的合成无影响,却能促进已有酶的活性。 相似文献
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Christopher C. Payne G.Mark Tatchell Ceris F. Williams 《Journal of invertebrate pathology》1981,38(2):273-280
A comparison was made of the dosage-mortality responses of larvae of Pieris brassicae and P. rapae to infection by P. brassicae granulosis virus (GV). Bioassays with first, second, third, and fourth-instar larvae of both species revealed a marked difference in susceptibility between instars and between species. Median lethal dosages (LD50s) for P. rapae larvae ranged from five capsules for the first instar to 662 capsules for the fourth instar. With P. brassicae, this range extended from 66 capsules to 2.3 × 107 capsules. The time-mortality responses of the two species were similar when fed virus dosages equivalent to an LD90. Median lethal times (LT50s) ranged from 5 days for first-instar larvae to 7–8 days for fourth-instar larvae. A comparison between a long-established laboratory stock of P. brassicae and a stock recently acquired from the field showed no significant difference in their susceptibility to GV. The implications of the pronounced species differences in susceptibility to GV infection are discussed in relation to the potential field control of P. rapae and P. brassicae. 相似文献
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Activities of the anti-oxidative enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase were studied in rat tissues to determine the ability of detergents both to solubilize the enzymes and also to stabilize enzyme activity. Rat brain, heart and liver were homogenized in 0.1M KCl, 0.1% sodium dodecyl sulfate, 0.1% lubrol, or 0.1% cetyl-trimethylammonium bromide. In general lubrol was more effective than the other solutions in solubilizing GPx and catalase. Lubrol and 0.1M KCl were equally effective in solubilizing SOD. The highest enzyme activities were (1) SOD: 2484 ng/mg (brain), 2501 ng/mg (heart), and 5586 ng/mg (liver); (2) GPx: 224 mU/mg (brain), 1870 mU/mg (heart), and 7332 mU/mg (liver); (3) catalase: 2.8 mU/mg (brain), 10.6 mU/mg (heart), and 309 mU/mg (liver). While cetyl trimethylammonium bromide is marginally better than sodium dodecyl sulfate in solubilizing active enzyme, neither ionic detergent has any advantage over lubrol or 0.1M KCl. For catalase and GPx, enzyme activity loss with time is biphasic. After initial, rapid activity loss (1–5 days for GPx and 7–10 days for catalase) the differences noted among the homogenizing solutions disappear and very little if any activity loss is noted over the next 2–3 weeks. For catalase and GPx, only baseline enzyme activity from t = 0 – 3 weeks is found in the most chaotropic solution, 0.1% sodium dodecyl sulfate while biphasic activity loss is most pronounced in 0.1% lubrol. These results may indicate active GPx and catalase species stabilized by a lipid-like environment. Correlatingin vitro catalase or GPx measurements within vivo anti-oxidative protection may underestimate tissue defences. 相似文献