Regulation of Catalase Activity in Leaves of Nicotiana sylvestris by High CO(2)

The effect of high CO₂ (1% CO₂/21% O₂) on the activity of specific forms of catalase (CAT-1, -2, and -3) (EA Havir, NA McHale [1987] Plant Physiol 84: 450-455) in seedling leaves of tobacco (Nicotiana sylvestris, Nicotlana tabacum) was examined. In high CO₂, total catalase activity decreased by 50% in the first 2 days, followed by a more gradual decline in the next 4 days. The loss of total activity resulted primarily from a decrease in CAT-1 catalase. In contrast, the activity of CAT-3 catalase, a form with enhanced peroxidatic activity, increased 3-fold in high CO₂ relative to air controls after 4 days. Short-term exposure to high CO₂ indicated that the 50% loss of total activity occurs in the first 12 hours. Catalase levels increased to normal within 12 hours after seedlings were returned to air. When seedlings were transferred to air after prolonged exposure to high CO₂ (13 days), the levels of CAT-1 catalase were partially restored while CAT-3 remained at its elevated level. Levels of superoxide dismutase activity and those of several peroxisomal enzymes were not affected by high CO₂. Total catalase levels did not decline when seedlings were exposed to atmospheres of 0.04% CO₂/5% O₂ or 0.04% CO₂/1% O₂, indicating that regulation of catalase in high CO₂ is not related directly to suppression of photorespiration. Antibodies prepared against CAT-1 catalase from N. tabacum reacted strongly against CAT-1 catalase from both N. sylvestris and N. tabacum but not against CAT-3 catalase from either species. This observation, along with the rapid changes in CAT-1 and the much slower changes in CAT-3 suggest that one form is not directly derived from the other.     

Rapid Kinetic Microassay for Catalase Activity

Catalase is a commonly assayed enzyme found in many bacteria and eukaryotes. In this report, we examined the applicability of a kinetic microassay to quantify catalase from two different sources. The assay was found to be linear over a wide range (0.1–1.0 units), but was limited at high values (>1 unit) by oxygen evolution. Nonetheless, the micorassay allows simultaneous evaluation of many samples (up to 96) in a short time (<5 min) and is thus well-suited to applications, such as high-throughput screening, where many parallel assays are required.     

水稻CAT与逆境应答关系及酶活性分析

过氧化氢酶(catalase,CAT)是一种四聚体血红素酶,主要存在于过氧化物酶体与乙醛酸循环体及相关细胞区域内.水稻中含有CAT1、CAT2和CAT3三种主要同工酶.它们在各组织不同的发育阶段,发挥着重要作用.在本研究解析了水稻过氧化氢酶同工酶基因在NaCl、NaHCO3、Na2CO3、PEG6000、H2O2、低温等逆境处理下mRNA表达特性.结果表明在不同的逆境下过氧化氢酶同工酶在表达上存在差异性.同时利用蛋白表达系统,对水稻过氧化氢酶CAT1和CAT3蛋白进行了纯化实验,对纯化的蛋白的酶活性分析的结果表明,CAT1和CAT3的酶活性没有十分显著的差别.     

Cytochemical Localization of Catalase Activity in Yeast Peroxisomes

Diaminobenzidine oxidation product occurred in peroxisomes and in the intracristate spaces of mitochondria. The reaction was inhibited only in peroxisomes when 3-amino-1,2,4-triazole was present, but cyanide and azide inhibited deposition in both kinds of organelles.     

A Salicylic Acid-Binding Activity and a Salicylic Acid-Inhibitable Catalase Activity Are Present in a Variety of Plant Species

Recently, it has been demonstrated that the salicylic acid (SA)-binding protein (SABP) from tobacco (Nicotiana tabacum) is a SA-inhibitable catalase (Z. Chen, H. Silva, D.F. Klessig [1993] Science 262: 1883-1886). Here we report the presence of SABP and SA-inhibitable catalase activity in Arabidopsis, tomato, and cucumber. The cucumber SABP has properties similar to the tobacco SABP, including binding affinity and specificity for SA.     

Catalase Activity and Post-anoxic Injury in Monocotyledonous Species

Three anoxia-intolerant species, Glyceria maxima, Juncus effususand Iris germanica (var. Quechei), and three anoxia-tolerantspecies Schoenoplectus lacustris, Acorus calamus and Iris pseudacoruswere chosen for investigation. Rhizomes of anoxia-intolerantspecies show increased catalase activities when returned toair after periods of prolonged anoxia. Levels of catalase remainedfairly constant in anoxia-tolerant species under the same conditions.In the anoxia intolerant G. maxima, the post-anoxic increasein catalase activity was reduced by circulating the anaerobicatmosphere. This treatment also reduced the ethanol contentof the tissue under incubation, and increased the survival ofthe rhizomes as seen in their ability to resume growth in thepost-anoxic phase. Exposure of anaerobic G. maxima rhizomesto ethanol vapour increased post-anoxic levels of catalase activityand when this produced a 5-fold increase always resulted indeath of the rhizomes. Acetaldehyde vapour applied in the sameway gave rise to increases in catalase activity followed byrapid death of the rhizomes. It is suggested that post-anoxic oxidation of anaerobicallyaccumulated ethanol may result in a surge of acetaldehyde production,which could exert a toxic effect on the recovering tissues.The possible role of catalase in an ethanol-oxidation reaction,which is well documented in animals, is discussed in the lightof the association between the natural accumulation of largeconcentrations of ethanol and subsequent post-anoxic death insome plant tissues. Key words: Catalase, post-anoxia, ethanol     

Monosialoganglioside Increases Catalase Activity in Cerebral Cortex of Rats

Monosialoganglioside (GM1) is a neuroprotective agent that has been reported to scavenge free radicals generated during reperfusion and to protect receptors and enzymes from oxidative damage. However, only a few studies have attempted to investigate the effects of GM1 on enzymatic antioxidant defenses of the brain. In the present study, we evaluate the effects of the systemic administration of GM1 on the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and on spontaneous chemiluminescence and total radical-trapping potential (TRAP) in cerebral cortex of rats ex vivo. The effects of GM1 on CAT activity and spontaneous chemiluminescence in vitro were also determined.

Animals received two injections of GM1 (50?mg/kg, i.p.) or saline (0.85% NaCl, i.p.) spaced 24?h apart. Thirty minutes after the second injection the animals were sacrificed and enzyme activities and spontaneous chemiluminescence and TRAP were measured in cell-free homogenates. GM1 administration reduced spontaneous chemiluminescence and increased catalase activity ex vivo, but had no effect on TRAP, SOD or GSH-Px activities. GM1, at high concentrations, reduced CAT activity in vitro. We suggest that the antioxidant activity of GM1 ganglioside in the cerebral cortex may be due to an increased catalase activity.     

人细胞毒性T淋巴细胞TALL-104抗癌细胞活性的检测

检测人细胞毒性T淋巴细胞TALL-104对癌细胞的杀伤活性以及此杀伤活性对白细胞介素-2的依赖性,动态观察其体外增殖能力.用台盼兰拒染法计算细胞扩增倍数;用MTT法检测细胞毒杀伤活性,实时观察细胞的杀伤过程.结果表明, 在200 IU/ml IL-2刺激下,TALL-104细胞增殖能力较强;在效靶比5∶ 1,作用时间为24 h,TALL-104细胞表现出对癌细胞MCF-7和A-431较高的杀伤率分别为50.4%和69.5%;当作用时间在72 h以内,效靶比不高于10∶ 1时,杀伤率随作用时间和效靶比的增加而明显升高(P<0.05);最大杀伤率分别为79.8%(MCF-7细胞)和90.4%(A431细胞).因此,TALL-104细胞体外增殖能力较强,其细胞毒活性不严格依赖于IL-2的存在.     

一种鉴定过氧化氢酶活性的铁染色法

采用聚丙烯酰胺凝胶电泳(PAGE)技术,建立了一种新的鉴定过氧化氢酶活性的方法──铁染色法．结果表明,细菌过氧化氢酶及牛肝过氧化氢酶显示单一的酶活性带．该方法操作简单、快速、灵敏度高、专一性强.是一种切实可行的鉴定过氧化氢酶活性染色法.     

Growth-Dependent Catalase Localization in Exiguobacterium oxidotolerans T-2-2T Reflected by Catalase Activity of Cells

A psychrotolerant and H₂O₂-resistant bacterium, Exiguobacterium oxidotolerans T-2-2^T, exhibits extraordinary H₂O₂ resistance and produces catalase not only intracellularly but also extracellularly. The intracellular and extracellular catalases exhibited the same enzymatic characteristics, that is, they exhibited the temperature-dependent activity characteristic of a cold-adapted enzyme, their heat stabilities were similar to those of mesophilic enzymes and very high catalytic intensity. In addition, catalase gene analysis indicated that the bacterium possessed the sole clade 1 catalase gene corresponding to intracellular catalase. Hence, intracellular catalase is secreted into the extracellular space. In addition to intracellular and extracellular catalases, the inner circumference of the cells showed the localization of catalase in the mid-stationary growth phase, which was observed by immunoelectron microscopy using an antibody against the intracellular catalase of the strain. The cells demonstrated higher catalase activity in the mid-stationary growth phase than in the exponential growth phase. The catalase localized in the inner circumference can be dissociated by treatment with Tween 60. Thus, the localized catalase is not tightly bound to the inner circumference of the cells and may play a role in the oxidative defense of the cells under low metabolic state.     

Catalase Activity in Rice Shoot Apex during Panicle Initiation

There was a gradual increase in the catalase activity in theshoot apices of the two rice varieties—Ratna and BAM 11,till panicle initiation. Peroxide content in the Ratna shootapices decreased with time and was low during and after panicleinitiation. In Ratna plants, exogenous application of cycloheximideand 3-amino-1,2,4-triazole resulted in a delay in panicle initiationwith a corresponding decrease in catalase activity. Exogenousapplication of hydrogen peroxide caused a rise in catalase activityand delayed panicle initiation in both Ratna and BAM 11 varieties.In BAM 11 plants treated with 28 consecutive short photoinductivecycles there was an earliness in flowering accompanied by anearly peak in catalase activity. (Received May 10, 1985; Accepted August 12, 1985)     

用Warburg法则定蜂花粉中过氧化氢酶活性

在国内首次利用经典的,国际上通用的仪器－Warburg呼吸计测定蜂花粉中氧化氢酶活性,该方法具有较好的精确度,重现性,变异系数小,建议可作为花粉中过氧化氢酶活性测定的法定方法。     

Changes in the Activity of Catalase (EC 1.11.1.6) in Relation to the Dormancy of Grapevine (Vitis vinifera L.) Buds

Catalase activity in grapevine (Vitis vinifera L.) buds cv. `Perlette.' increased to a maximum in October and thereafter decreased within 3 months to less than half its maximal rate. The decrease in catalase activity coincided with the decline in temperature during winter. The rate of sprouting of buds forced at 23°C was negatively related to the activity of catalase. Artificial chilling of grapevine canes at 5°C resulted in a 25% decrease of catalase activity in the buds after 3 days and 31% after 17 days. The activity of catalase increased to the control level only 96 hours after removing canes from 5°C to room temperature. Efficient buddormancy breaking agents, such as thiourea and cyanamide decreased catalase activity to 64 and 50% of the controls respectively, while the activity of peroxidase remained the same under those conditions. A less efficient dormancy breaking agent dinitro-ortho-cresol, did not decrease catalase activity.     

Synthesis and Cytotoxic Activity Against a Non-small-cell Bronchopulmonary Carcinoma Line (NSCLC-N6) of Benzofuran Enantiomeric Derivatives

The synthesis of 2-isopropenyl-2,3-dihydrobenzofuranic enantioisomers is described. Ortho-(2-hydroxy-3-methylbut-3-enyl)phenol synthons are used as precursors to these structures. In vitro antitumor activity against a non-small-cell bronchopulmonary carcinoma line (NSCLC-N6) of these enantioisomers has been investigated.     

Catalase Activity and Thiobarbituric Acid Reactive Substances (TBARS) Production in a Rat Model of Diffuse Axonal Injury. Effect of Gadolinium and Amiloride

This study evaluated the effect of mechanogated membrane ion channel blockers on brain catalase (CAT) activity and thiobarbituric acid reactive substances (TBARS) production after traumatic brain injury (TBI). A weight drop trauma model was used. Controls were sham-operated and received no weight drop. Gadolinium (GAD) or amiloride (AMI) were administered to control and experimental rats (30 min after TBI). Brain CAT activity and TBARS production were measured. When blood vessels were washed out with saline perfusion brain CAT activity significantly increased up to 6 h after trauma, decreasing significantly by 24 h; GAD or AMI administration preserved CAT activity 24 h after TBI. TBARS production increased after trauma, this effect being significantly reversed by GAD or AMI administration. GAD significantly decreased TBARS production in control animals. Mechanogated membrane ion channels may be involved in the genesis of the ionic disruption leading to oxidative stress and other secondary injury processes in head trauma.     

甲醇对酵母过氧化氢酶活性的影响机理研究

将酵母过氧化氢酶加入一定比例的甲醇,测定其活性变化。结果表明:在含2%甲醇时酶活比对照提高4026%。将粗酶液用70%饱和度的硫酸铵盐析后离心所得的上清液再加入硫酸铵至80%饱和度,离心的沉淀溶解在缓冲液中,上SephadexG75柱,分离出的有酶活性的蛋白峰经电泳得一条蛋白带,说明过氧化氢酶已经被提纯到电泳纯。光谱分析发现,甲醇处理后过氧化氢酶纯酶的吸收光谱和荧光发射光谱与未经处理的比较基本不变,而差示光谱出现明显的正峰和负峰。由动力学分析可知,在甲醇中,过氧化氢酶的Vmax和Km值均有不同程度提高 。     

Catalase deficiency may complicate urate oxidase (rasburicase) therapy

Patients with low (inherited and acquired) catalase activities who are treated with infusion of uric acid oxidase because they are at risk of tumour lysis syndrome may experience very high concentrations of hydrogen peroxide. They may suffer from methemoglobinaemia and haemolytic anaemia which may be attributed either to deficiency of glucose-6-phosphate dehydrogenase or to other unknown circumstances. Data have not been reported from catalase deficient patients who were treated with uric acid oxidase. It may be hypothesized that their decreased blood catalase could lead to the increased concentration of hydrogen peroxide which may cause haemolysis and formation of methemoglobin. Blood catalase activity should be measured for patients at risk of tumour lysis syndrome prior to uric acid oxidase treatment.     

Catalase deficiency may complicate urate oxidase (rasburicase) therapy

Patients with low (inherited and acquired) catalase activities who are treated with infusion of uric acid oxidase because they are at risk of tumour lysis syndrome may experience very high concentrations of hydrogen peroxide. They may suffer from methemoglobinaemia and haemolytic anaemia which may be attributed either to deficiency of glucose-6-phosphate dehydrogenase or to other unknown circumstances. Data have not been reported from catalase deficient patients who were treated with uric acid oxidase. It may be hypothesized that their decreased blood catalase could lead to the increased concentration of hydrogen peroxide which may cause haemolysis and formation of methemoglobin. Blood catalase activity should be measured for patients at risk of tumour lysis syndrome prior to uric acid oxidase treatment.