马缨丹叶提取液对水葫芦叶片中超氧物歧化酶活性和过氧化氢积累的影响

水葫芦[Eichhornia crassipes（Mart）Solms]是世界上繁殖最快、危害最严重的多年生水生杂草之一。为了避免化学除草剂对水体的污染,生物防治已成为当前水葫芦治理的重要方向。马缨丹（Lantana camara）是马鞭草科的一种植物,其叶片提取物对水葫芦有很强的毒性。研究结果表明：经马缨丹叶提取液处理的水葫芦叶片中,超氧物歧化酶（SOD）活性与H2O2浓度均显著升高,但过氧化氢酶的活性受到抑制,膜脂过氧化程度明显增加。H2O2的组织化学染色结果表明H2O2在气孔细胞中有异常高的积累,H2O2过量产生同时导致水葫芦叶片失绿与细胞死亡。因此,氧胁迫可能是马缨丹提取液对水葫芦毒害的主要原因之一。     

四棱豆不同节位各器官中SOD活性的测定

测定实验表明 :位于四棱豆植株中部节位叶片中的SOD活性高于植株下部和上部节位叶片中的SOD活性 ;而位于下部节位豆荚和种子中的SOD活性要高于位于上部节位豆荚和种子中的SOD活性 ,且随着结荚部位升高 ,SOD活性呈降低趋势。     

活性氧所致超氧化物歧化酶肽链断裂的观察

探究活性氧所致铜锌超氧化物歧化酶（ＳＯＤ）肽链断裂的情况。将过氧化氢或抗坏血酸－Ｆｅ（Ⅲ）分别作用于马来酰亚胺标记的ＳＯＤ,然后用高效液相反相色谱（ＲＰＨＰＬＣ）分析,经１ｍｍｏｌ／ＬＨ２Ｏ２处理后ＳＯＤ用ＲＰ－ＨＰＬＣ分离出二个肽段,用顺磁共振检测显示只有一个肽段具有马来酰亚胺信号,经５ｍｍｏｌ／ＬＨ２Ｏ２处理后ＳＯＤ有四个肽段生成,其中有一个肽段具有马来酰亚胺信号,用５ｍｍｏｌ／Ｌ抗坏血酸和０．０１ｍｍｏｌ／ＬＦｅＣｌ３处理后ＳＯＤ有三个肽段生成,用５０ｍｍｏｌ／Ｌ抗坏血酸及１．０ｍｍｏｌ／ＬＦｅＣｌ３处理后ＳＯＤ也产生相同的三个肽段,只是肽段的量多．结果提示Ｈ２Ｏ２所致ＳＯＤ肽链断裂无“定点”现象,而抗坏血酸－Ｆｅ（Ⅲ）所致ＳＯＤ肽链断裂呈“定点”断裂。     

极谱氧电极法测定超氧化物歧化酶活性的改进

对SOD的极谱氧电极测定法做了如下修改:a.室温测定,b.酶活性用标准SOD标定,c.反应在磷酸缓冲液中进行,d.增大邻苯三酚的用量.改进后克服了易在电极薄膜表面产生气泡等问题,测定灵敏度及线性范围增大.     

Normolipidaemic Activity of Liposomal-Encapsulated Superoxide Dismutase in Rats

To determine the regulatory effects of superoxide dismutase (SOD) on lipid metabolism a simple model of hyperlipidaemia induced by a hypercholesterolaemic (HCT) diet in rat was used. In animals fed a HCT diet, triglyceride (TG) were increased by 126%, total cholesterol (TCT) by 40%, very low density lipoprotein (VLDL) by 124% and the TCT/HDL ratio by 82%. The procedure would therefore appear to model some of the risk factors of atherogenesis.

In animals fed a hypercholesterolemic diet, liposomal Cu-SOD (200μg/kg i. m. every two days; 1000 μg/kg i. m./day) decreased TG by 29 and 49%, TCT by 14 and 36%, TCT/HDL ratio by 32 and 60%, VLDL by 52 and 55% respectively and increased high density lipoprotein cholesterol (HDL-C) by 17 and 46% respectively.

The present experiments show therefore that the administration of liposomal SOD has a marked effect on lipid parameters (particularly TCT and TG) and might therefore reduce the atherogenic risk by increasing HDL and decreasing VLDL and cholesterol atherogenicity ratio (CAR).     

几种外源因子对大豆幼苗SOD活性的影响

高氧能促使大豆幼苗细胞内产生O_2~+速率增加,同时又使幼苗内SOD活性水平提高,以减轻O_2~+增加所引起的细胞伤害。高氧诱发O_2~+同时发生在叶绿体、线粒体和细胞溶质中,与细胞呼吸水平无明显相关。棓酸丙酯有清除体内O_2~+的能力,当浓度在1μmol/L时,能减轻大豆幼苗的氧伤害。相反,DDC是SOD的有效抑制剂,当它的浓度大于5 mmol/L时,显著抑制大豆幼苗SOD活性,增加了体内O_2~+的积累,影响了幼苗的正常生长以及幼苗氧伤害的加剧。     

铜、锌对水稻幼苗生长及超氧物歧化酶的影响

用缺Cu或Zn,与缺Cu、Zn的木村B营养溶液培养杂交水稻威优48(V_(48)),威优49(V_(49))与常规稻竹系26(ZX_(26))幼苗至七叶期。缺Cu的稻苗,上部新生叶(六、七叶)先端扭曲,叶尖枯黄。缺Zn与缺Cu、Zn的稻苗,六、七叶脉间全部褪绿,植株矮小,根系衰退。凡是缺素培养的稻苗,根与叶的超氧物歧化酶(SOD)活性均显著减弱,叶绿体基粒与间质片层明显减少,缺Cu、Zn的叶绿体还出现较大的淀粉“液泡”。经凝胶电泳,显示出水稻SOD有4组活性带,缺Cu或Zn与缺Cu、Zn使迁移率较高的3组活性带的活性明显减弱。     

Physiological Targets of Superoxide Anion and Hydrogen Peroxide in Reperfusion Injury

Current dogma associates reperfusion injury with the introduction of reactive oxygen species (ROS) into the ischemic tissue. The sources of ROS under discussion are xanthine oxidase in the endothelium of small vessels and/or invaded polymorphonuclear leukocytes (PMN). The beneficial effects of both superoxide dismutase and catalase suggest an involvement of superoxide anions and hydrogen peroxide in this pathophysiological process, without describing the targets of their action.

In our work we demonstrate that these two ROS effectively interact with two enzymes. Superoxide anions inhibit soluble guanylate cyclase. Its product, cGMP, is considedred to antagonize platelet activation and to cause smooth muscle relaxation. Thus O₂ can intensify platelet aggregability and small vessel occlusion. Similar effects are elicited by H₂O₂, which shifts the dose response curve of several agonists towards smaller concentrations by activating cyclooxygenase. This enzyme provides the substrate for thromboxane synthase which generates TxA₂, the most potent physiologically occurring platelet aggregating and smooth muscle contacting agonist.

These results lead us to the suggestion that the influence of the oxidative burst of PMN in the phenomenon of reperfusion injury should be reconsidered.     

Characterization of Hydrogen Peroxide and Superoxide Degrading Pathways of Aspergillus Niger Catalase: A Steady-State Analysis

The oxidized intermediates generated upon exposure of Aspergillus niger catalase to hydrogen peroxide and superoxide radical fluxes were examined with UV-visible spectrophotometry. Hydrogen peroxide and superoxide radical were generated by means of glucose/glucose oxidase and xanthine/xanthine oxidase systems. Serial overlay of absorption spectra in the Soret (350-450 nm) and visible regions (450-700 nm) showed that the decomposition of hydrogen peroxide by the catalase of Aspergillus niger can proceed through one of two distinct pathways: (i), the normal “catalatic” cycle consisting of ferric catalase → Compound I → ferric catalase; (ii), a longer cycle where superoxide radical transforms Compound I to Compound II which is then converted to the resting ferric enzyme via Compound III. The latter sequence of reactions ensures that the catalase of Aspergillus niger restores entirely its activity upon exposure to low levels of superoxide radicals due to the actions of oxidases.     

超氧化物歧化酶在反胶束体系中稳定性的研究

目的：考察反胶束体系组成对超氧化物歧化酶(SOD)抗氧化活性的影响。方法：以大豆磷脂氧化产生的氧自由基量为检测指标,考察温度、有机试剂以及表面活性剂浓度对反胶束体系中超氧化物歧化酶抗氧化活性的影响。结果：60℃时,反胶束中超氧化物歧化酶的抑制率由在水溶液中的52．48%升到75．38%,即SOD包封于反胶束中后热稳定性明显提高。表面活性剂可有效阻止有机溶剂对SOD的变性作用,SOD是不具界面活性的酶。结论：超氧化物歧化酶在反胶束体系中稳定性及抗氧化活性增强。     

脱氧核糖核酸对机体内超氧化物岐化酶和过氧化物酶活性影响初步研究

超氧化物岐化酶（SOD）和过氧化物酶（POD）是机体内重要的抗氧化酶系之一,其作用在于消除体内的自由基,防止自由基对细胞结构的损伤。它们的活性随增龄而下降,因此自由基不断损伤细胞结构,累积最终导致细胞衰亡和动物机体衰老,老龄小鼠服用DNA一段时间后,其体内SOD和POD的活性均显著提高,因而其衰老速度可能得到一定程度的延缓。     

Bisphenol-A Can Inhibit the Enzymatic Activity of Human Superoxide Dismutase

Bisphenol-A (BPA), a synthetic xenoestrogen, is currently being used to produce a wide variety of consumer products. Humans as well as animals are exposed to this ubiquitous compound through ingestion, inhalation, and dermal exposure. The effect of this compound on superoxide dismutase (SOD), an antioxidant enzyme, isolated from human blood was studied using an enzyme inhibition assay. The mode of interaction of BPA on SOD was investigated using modeling and docking studies. Purified human SOD from erythrocytes was used to study the enzyme inhibition assay of BPA. Molecular level interactions of BPA on SOD were also analyzed by modeling and docking studies. Our study demonstrates that BPA has an inhibitory effect on SOD. The docking results showed that it could bind to the active site residues of SOD and could interfere with the catalytic activity of the enzyme. Our study reveals for the first time that BPA can directly inhibit the enzymatic activity of human SOD and thus impairs the free radical scavenging mechanism.     

From Haemocuprein to Copper-Zinc Superoxide Dismutase: A History on the Fiftieth Anniversary of the Discovery of Haemocuprein and the Twentieth Anniversary of the Discovery of Superoxide Dismutase

Haemocuprein was discovered fifty years ago by T. Mann and D. Keilin as a copper protein of red blood cells, later named erythrocuprein. Superoxide dismutase was discovered twenty years ago by J.M. McCord and I. Fridovich as an enzymatic activity in preparations of carbonic anhydrase or myoglobin that inhibited the aerobic reduction of cytochrome c by xanthine oxidase. Astonishingly the superoxide dismutase proved to be haemocuprein. Around this time zinc was found in haemocuprein, in equimolar amount to the copper. Haemocuprein thus became copper-zinc superoxide dismutase after thirty years as an obscure cupropro-tein of red blood cells. This historical article is a tribute to the achievement of J.M. McCord and I. Fridovich. Their discovery of superoxide dismutase revolutionized the study of oxygen free-radicals in biochemistry.     

Influence of Hyperthyroidism on Superoxide Radical and Hydrogen Peroxide Production by Rat Liver Submitochondrial Particles

Administration of daily doses of 0.1 mg of 3, 5, 3'-triiodothyronine (T₃)/kg body weight for 3 consecutive days to fed rats elicited a calorigenic response in the animals, in concomitance with a 36% increase in the rate of O₂ consumption by the liver. In these conditions, liver submitochondrial particles (SMP) from T₃-treated rats exhibited marked increases in the rate of superoxide radical generation, both in the presence of NADH (142%) or succinate (152%). Furthermore, liver SMP from hyperthyroid animals released hydrogen peroxide at higher rates than those of euthyroid rats, either under basal conditions or in the succinate-supported process, both in the absence and presence of antimycin-A. It is concluded that the hyperthyroid state in the rat leads to a drastic enhancement in the capacity of liver mitochondria to produce active oxygen species, which correlates with the elevated respiratory rate observed in the intact organ.     

Effect of Some Environmental Pollutants on the Superoxide Dismutase Activity in Lemna

Exposure of Lemma sp. to SO₂ resulted in an increased activity of superoxide dismutase. About 3 to 4 fold increase in the activity was observed within 30 minutes after the plants were fumigated with 10 ml/l of SO₂. Paraquat, a well known superoxide generator, doubled the enzyme activity after 1 hour of treatment with 0.1 mM paraquat. Superoxide dismutase activity was also enhanced by cadmium treatment but the response was not immediate. Optimum increase in the activity of enzyme was observed after 4 days of treatment with 40 mg/l of cadmium in the medium. Treatment with H₂O₂ very clearly inhibited the activity of superoxide dismutase in Lemna.     

Peroxide metabolism in the cestodes Hymenolepis diminuta and Moniezia expansa

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.     

Age-Dependent Resistance to the Toxic Effects of Paraquat in Relation to Superoxide Dismutase Activity in Rat Lung

Young rats are much more resistant to the toxic effects of orally-administered paraquat than are older rats. The possible relation of this phenomenon to the activity of superoxide dismutase in lung is discussed.     

鳗弧菌侵染对青蛤溶菌酶和超氧化物岐化酶活性的影响

青蛤样品分别注射鳗弧菌和生理盐水,在注射后3 h、6 h、12 h、24 h、36 h和48 h取不同处理组血清,测定其溶菌酶(LSZ)和超氧化物歧化酶(SOD)活性,分析鳗弧菌对青蛤体内免疫相关酶活性的影响.结果表明,鳗弧菌感染组的青蛤血液中LSZ和SOD活性均有显著升高的趋势,SOD在12 h时达到最高,LSZ在36 h达到最高,均与对照组差异显著(P<0.05),随后呈现下降趋势.表明鳗弧菌对青蛤的LSZ与SOD酶活性影响较大,对其免疫防御系统有明显的刺激作用.     

锰超氧化物歧化酶的催化原理与酶活性调节机制

锰超氧化物歧化酶(MnSOD)催化两分子超氧自由基歧化为分子氧和过氧化氢。超氧自由基被Mn³⁺SOD氧化成分子氧的反应以扩散的方式进行。超氧自由基被Mn²⁺SOD还原为过氧化氢的反应以快循环和慢循环两条途径平行进行。在慢循环途径中,Mn²⁺SOD与超氧自由基形成产物抑制复合物,然后该复合物被质子化而缓慢释放出过氧化氢。在快循环途径中,超氧自由基直接被Mn²⁺SOD转化为产物过氧化氢,快速循环有利于酶的复活与周转。本文提出温度是调节锰超氧化物歧化酶进入慢速或者快速循环催化途径的关键因素。随着在生理温度范围内的温度升高,慢速循环成为整个催化反应的主流,因而生理范围内的温度升高反而抑制该酶的活性。锰超氧化物歧化酶的双相酶促动力学特性可以用该酶保守活性中心的温度依赖性配位模型进行合理化解释。当温度降低时,1个水分子(或者OH^-)接近Mn、甚至与Mn形成配位键,从而干扰超氧自由基与Mn形成配位键而避免形成产物抑制。因此在低温下该酶促反应主要在快循环通路中进行。最后阐述了几种化学修饰模式对...     

过氧化氢对铜锌超氧化物歧化酶活性及某些理化性质的影响

用H_2O_2作用于牦牛红细胞铜锌超氧化物歧化酶。观察到酶活性随H_2O_2浓度升高及作用时间增加而下降;酶分子连接的铜和锌有所丢失;PAGE图谱中三条酶活性带成为四条酶活性带;等电点下降;680nm处表征二价铜光学性质的可见光吸收减弱;紫外吸收增加,表现为增色效应;内源性荧光减弱;在含有3.0mol/LKCl的PH3.8—5.4琥珀酸缓冲液中溶解度下降;酶对胰蛋白酶水解的敏感性增加。