Purification and characterization of a novel sigma-class glutathione S-transferase of the fall webworm, Hyphantria cunea

Abstract:  An enzyme that possesses glutathione S -transferase (GST) activity was found in the fall webworm, Hyphantria cunea . The enzyme was purified to homogeneity for the first time by ammonium sulphate fractionation and affinity chromatography. The N-terminal sequence of the purified protein was similar to those of Sigma-class GSTs. The purified GST retained more than 75% of its original GST activity after incubation at pH 5–8. Incubation for 30 min at temperatures below 50°C scarcely affected the activity. The enzyme was able to catalyse the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, a universal substrate for GST, as well as with 4-hydroxynonenal, a product of lipid peroxidation.     

Lysis of Yeast Cells Showing Low Susceptibility to Zymolyase

Lysis of commercial baker’s yeast cells was examined using Zymolyase. The lysis was stimulated by the addition of sodium sulfite or potassium chloride or both. The effect of potassium chloride was less than that of sodium sulfite, but the two compounds acted synergistically. The cells were effectively lysed by Zymolyase in the presence of 0.1 M sodium sulfite and 0.8 M potassium chloride. The extent of lysis was similar to that of brewery yeast cells obtained from a brewhouse. Cells pretreated with sodium sulfite did not show much of an increase in susceptibility to Zymolyase, but were effectively lysed by the enzyme in the presence of potassium chloride. Potassium chloride stimulated lysis only in the presence of Zymolyase. Yeast cells treated with cupric ions in the presence of sodium sulfite became highly susceptible to Zymolyase, suggesting irreversible destruction of the sodium sulfite-sensitive and potassium chloride-sensitive structure of the cell wall.

Cells of Saccharomyces cerevisiae prepared under various culture conditions were completely lysed by Zymolyase in the presence of sodium sulfite or potassium chloride or both.     

利用生命表评价白蛾周氏啮小蜂对美国白蛾的控制作用

为了研究白蛾周氏啮小蜂对侵入性害虫-美国白蛾的控制作用,在山东省烟台市美国白蛾发生区,选择美国白蛾发生程度中等的两块样地,一块样地作为释放白蛾周氏啮小蜂防治美国白蛾的防治区,另一块样地作为对照区。应用生命表技术,连续2年共4代对美国白蛾种群数量进行定点观察。防治区每代美国白蛾在化蛹初期和化蛹盛期各放蜂1次,即每代美国白蛾共放蜂2次。将2年的第1代和第2代观测数据分别综合平均,制成4个生命表。结果表明,在放蜂防治区,第1代和第2代美国白蛾的种群趋势指数（I）分别为0.29和0.14,说明下代美国白蛾种群数量将急剧下降;放蜂区的I值显著小于对照区的8.74和4.48。生命表研究结果清楚地表明,通过人工释放白蛾周氏啮小蜂能够达到良好的控制美国白蛾的效果。     

低温对美国白蛾越冬蛹的影响研究

美国白蛾Hyphantria cunea Drury是我国唯一一种被农业、林业共同列为检疫对象的害虫。本论文通过2010与2011年室内测定和室外调查的一系列研究表明,美国白蛾蛹在不同低温处理下随着处理时间的延长存活率逐渐降低。其中,-10℃下处理30 h后几乎没有越冬蛹存活,-15℃下处理3 h后越冬蛹的存活率低于5%,-20℃处理25 min后越冬蛹几乎没有羽化为成虫的个体。0℃低温处理对越冬蛹的低温存活率有重要影响,且随着0℃下处理的时间长短而发生变化,在0℃下处理时间越长则在-10℃下存活率越高。在0℃下处理150 min以后,存活率随处理时间的延长差异不显著。     

Lipid peroxidative damage on cadmium exposure and alterations in antioxidantsystem in rat erythrocytes: A study with relation to time

Cadmium induced lipid peroxidation (LPO) and the activity of antioxidantenzymes after the administration of a single dose of CdCl 2 (0.4 mg kg body wt, ip) was studied in rat erythrocytes.Cd intoxication increased erythrocyte LPO along with a decrease insuperoxide dismutase (SOD) up to three days of Cd treatment. Thedecrease in erythrocyte catalase (CAT) activity was marked within9 h of Cd intoxication. After three days of Cd treatment, LPOdecreased towards normal, along with an increase in erythrocyteSOC and CAT activity. Blood glutathione (GSH) decreased significantlywithin 24 h of Cd treatment, followed by an increase towards normal.Erythrocyte glutathione S-transferase (GST) activity increased up to10 days of Cd intoxication, probably in an attempt to reduce Cd toxicity.Serum glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase(SALP) and serum bilirubin increased up to 10 days of Cd intoxication.Blood urea increased significantly up to three days, followed by a decreasetowards normal. The results show that Cd induced LPO was associated with adecrease in antioxidant enzymes and GSH in erythrocytes; as these antioxidantsincrease in erythrocytes with recovery from Cd intoxication, the Cd inducedLPO reversed towards normal. The increase in the SGPT, SALP and serum bilirubincorrelated with LPO. The results suggest that Cd intoxication induces oxidativestress and alters the antioxidant system, resulting in oxidative damage torat erythrocytes. © Rapid Science 1998     

Effect of Cadmium Ions on Antioxidant Defense System in Sunflower Cotyledons

Sunflower (Helianthus annuus L.) seeds were germinated and grown in the presence of 50, 100 and 200 μM CdCl₂. The lower concentration (50 μM) of Cd² ions produced slight decrease in reduced glutathione (GSH) content and overall increase (except superoxide dismutase) in antioxidant enzyme activities, and in H₂O₂ concentration. Chlorophyll content, lipid peroxidation and protein oxidation were not affected under 50 μM CdCl₂. GSH content was diminished under 100 and 200 μM CdCl₂, and except for superoxide dismutase, which activity remained unaltered, overall decreases in the antioxidant enzyme activities (catalase, ascorbate peroxidase, dehydroascorbate peroxidase, glutathione reductase) and in guaiacol peroxidase were observed. These Cd² concentrations caused a decrease in chlorophyll content as well as an increase in lipid peroxidation, protein oxidation and H₂O₂ concentration. All the observed effects were more evident with the highest concentration of cadmium chloride used. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molecular Docking Studies and the Effect of Fluorophenylthiourea Derivatives on Glutathione-Dependent Enzymes

Cancer is a serious problem affecting the health of all human societies. Chemotherapy refers to the use of drugs to kill cancer or the origin of cancer. In the past three decades, researchers have studied about proteins and their roles in the production of cancer cells. Glutathione S-transferases (GSTs) are a superfamily of enzymes that play a key role in cellular detoxification, protecting against reactive electrophiles attacks, including chemotherapeutic agents. Glutathione reductase (GR) is an important antioxidant enzyme involved in protecting the cell against oxidative stress. In this current study, GST and GR enzymes were purified from human erythrocytes using affinity chromatography. GR was obtained with a specific activity of 5.95 EU/mg protein and a 52.38 % yield. GST was obtained with a specific activity of 4.88 EU/mg protein and a 74.88 % yield. The effect of fluorophenylthiourea derivatives on the purified enzymes was investigated. Afterward, K_I values were found to range from 23.04±4.37 μM–59.97±13.45 μM for GR and 7.22±1.64 μM–41.24±2.55 μM for GST. 1-(2,6-difluorophenyl)thiourea was showed the best inhibition effect for both GST and GR enzymes. The relationships of inhibitors with 3D structures of GST and GR were explained by molecular docking studies.     

Effect of cisplatin on mitochondrial protein, glutathione, and succinate dehydrogenase in Dalton lymphoma-bearing mice

Cisplatin treatment of tumor-bearing mice resulted a significant decrease of protein in the tissues studied (liver, kidney, and Dalton lymphoma) and also in their mitochondrial fractions. As compared to respective tissues, the protein decrease was noted to be more conspicuous in their mitochondrial fractions. Similarly, mitochondrial glutathione also decreased significantly in the tissues. However, succinate dehydrogenase activity was selectively decreased in the kidney and Dalton lymphoma cells, whereas in liver it remained almost unchanged. An increase in serum urea concentration and kidney mitochondrial lipid peroxidation was also observed after cisplatin treatment. It is suggested that the cisplatin-induced biochemical changes in mitochondria involving mitochondrial protein, glutathione, and succinate dehydrogenase could be the important potent cellular sites contributing to toxicity/cytotoxicity after cisplatin treatment. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of Isoproterenol Administration on Rat Heart Glutathione Status

The intraperitoneal administration of 3, 10 and 80 mg/Kg isoproterenol produced in the cardiac muscle a dose dependent increase of GSH content and a slight elevation of GSSG content. In addition, the treatment with the catecholamine at the doses of 3 and 10 mg/Kg produced a slight decrease of the mixed glutathione disulfides level, whilst at the dose of 80 mg/Kg, this effect was more pronounced. These changes were not accompanied by modifications of the activities of the enzymes glutathione peroxidase, glutathione reductase and glutathione S-transferase.     

Effect of Low-Intensity Laser Radiation on the Lipid Peroxidation in Wheat Callus Culture

The effect of low-intensity laser radiation on the accumulation of secondary products of lipid peroxidation was studied in wheat (Triticum aestivum L.) tissue culture. A five-min-long callus irradiation by the helium-neon laser light with the wavelength = 632.8 nm and the intensity of 10 mW resulted in an increase in the accumulation of the products of reaction with thiobarbituric acid (TBA-reactive products). The effect was less pronounced within two days after laser treatment, but even in this case the content of TBA-reactive products was greater than in the control. The data obtained confirm that the low-intensity laser radiation can induce lipid peroxidation processes in plant tissues.     

Effect of the lipid peroxide reaction caused by repeated cold stress on cisplatin-induced nephrotoxicity

The peroxide reaction in mouse kidney was examined in order to determine the relationship between the lipid peroxide reaction caused by SART (specific alternation of rhythm in temperature) stress and that caused by drug administration. After exerting SART stress for one wk on 6-wk-old male ddY mice (stress group), the peroxide reaction generated by the administration of a single dose of cis-diamminedichloroplatinum (cisplatin: CDDP, 10 mg/kg, ip) into SART-stressed mice (stress + CDDP group) was compared with the reaction of CDDP-administered nonstressed mice (CDDP group), saline-administered nonstressed mice (saline group), and saline-administered SART-stressed mice (stress + saline group). Lipid peroxidation in the kidneys was significantly higher in the stress group upon cessation of stress exertion than in the normal group. However, no significant difference in the lipid peroxide level after administration of CDDP was observed between the CDDP groups. The renal glutathione levels were significantly different between the CDDP groups and the saline administered groups. These results indicate that the peroxide reaction is generated in the kidneys by stress, but stress has no effect on the peroxide damage caused by CDDP administration. However, the contribution of stress to renal function impairment requires further evaluation.     

柑橘全爪螨田间种群敏感性测定及三种主要解毒酶活性比较

为明确重庆地区柑橘全爪螨Panonychus citri(McGregor)对常用杀螨剂的抗性水平,本研究采用阿维菌素、哒螨灵、三唑锡、螺螨酯4种不同类型杀螨剂对柑橘全爪螨重庆北碚种群、璧山种群、武隆种群和忠县种群进行了田间敏感性测定。结果表明,柑橘全爪螨4个种群对三唑锡表现最不敏感,致死中浓度LC50在209.9～370.9mg/L之间。璧山种群对阿维菌素敏感性最高,武隆种群和忠县种群对阿维菌素的相对抗性分别达12倍和11倍。哒螨灵监测结果表明,北碚种群的抗性水平显著高于其他3个种群。而北碚种群对螺螨酯的LC50仅为1.2mg/L,显著低于其他种群。柑橘全爪螨4个种群解毒酶活性研究发现,解毒酶活性的高低与不同种群抗性水平之间并没有明显相关性,这可能同各地区施药背景不同、综合防治措施不同、各杀螨剂作用机理不同、不同种群体内代谢抗性及靶标抗性水平差异有关。     

白蛾周氏啮小蜂毒液对美国白蛾蛹血细胞免疫的影响

【目的】明确白蛾周氏啮小蜂Chouioia cunea毒液对其寄主美国白蛾Hyphantria cunea蛹细胞免疫的影响。【方法】采用Na_2-EDTA分离美国白蛾蛹颗粒细胞,尼龙毛法分离浆血细胞,再利用细胞离体培养法,测评了白蛾周氏啮小蜂毒液对寄主美国白蛾两种血细胞包囊作用和吞噬作用的影响。【结果】美国白蛾颗粒细胞的包囊指数强于浆血细胞。白蛾周氏啮小蜂毒液对颗粒细胞和浆血细胞的包囊指数均有明显的抑制作用,毒液浓度越大,抑制作用越强,两种血细胞的包囊作用均呈先增长后降低的趋势。在所有浓度毒液处理下,颗粒细胞的包囊指数在12 h时最强。未经小蜂毒液处理的浆血细胞包囊指数在15 h时达到最强,但经浓度为0.01~0.03 VRE/μL的毒液处理后浆血细胞的包囊指数在12 h时达到最强,而经浓度为0.04~0.10 VRE/μL的毒液处理后包囊指数在9 h时最强。白蛾周氏啮小蜂毒液对美国白蛾蛹颗粒细胞的吞噬作用强于浆血细胞。毒液对两种血细胞的吞噬能力均有明显的抑制作用,但毒液处理对浆血细胞的吞噬作用影响较小。【结论】白蛾周氏啮小蜂毒液可以抑制美国白蛾蛹颗粒细胞和浆血细胞的包囊作用和吞噬作用,且随着毒液浓度的增加,两种血细胞的免疫作用显著下降。     

Exercise,depletion of antioxidants and antioxidant manipulation

Strenuous physical activity is known to increase the production of reactive oxygen species (ROS), associated with depletion of antioxidant defence. In the present work we evaluated the level of lipid peroxidation and antioxidant components in blood of sportsmen under resting conditions and compared the data obtained with those in age- and sex-matched sedentary controls. A significant increase was noted in the levels of thiobarbituric acid reactive substances (TBARS) and conjugated dienes while a decrease was observed in ascorbic acid and glutathione levels in sportsmen. α-Tocopherol was unaltered in plasma of sportsmen as compared to controls. The activity of superoxide dismutase was increased (52 per cent) and glutathione peroxidase was decreased (43 per cent) in the erythrocytes of sportsmen compared to controls. Basal glutathione levels were negatively correlated with conjugated dienes and maximal oxygen uptake (VO_2max) of the subjects. Dietary supplementation with antioxidant vitamins has been shown to be beneficial in combating oxidative stress without enhancing performance while exogenous glutathione was found to influence the endurance capacity of athletes. Such studies demonstrate the critical role played by glutathione and suggest that intervention trials should include a mixture of antioxidants rather than a single antioxidant. Copyright © 1998 John Wiley & Sons, Ltd.     

Effects of chronic quercetin treatment on hepatic oxidative status of spontaneously hypertensive rats

The effects of chronic administration of an oral daily dose of quercetin (10 mg Kg^–1), the most abundant dietary flavonoid, were investigated on hepatic oxidative status in spontaneously hypertensive rats and normotensive Wistar Kyoto rats. Decreased liver glutathione peroxidase activity, increased liver total glutathione levels and increased both hepatic and plasmatic malondialdehyde concentrations were observed in spontaneously hypertensive rats when compared to Wistar Kyoto rats. In spontaneously hypertensive rats, treatment with quercetin for 5 weeks reduced blood pressure, increased glutathione peroxidase activity and reduced both plasma and hepatic malondialdehyde levels. However, none of these effects were observed in Wistar Kyoto rats. In conclusion, quercetin shows both antihypertensive and antioxidant properties in this model of genetic hypertension.     

美国白蛾天敌研究进展

美国白蛾Hyphantria cunea(Drury)是国家林业和草原局的重点防控对象,也是我国重大外来林业检疫性有害生物.现阶段美国白蛾在我国的种群密度持续增加和扩散,缺乏有效天敌的控制应该是重要的原因之一.本文综述了国内、外美国白蛾的捕食性和寄生性天敌的种类.捕食性天敌主要包括昆虫、蜘蛛、两栖类和鸟类,整理出国外报道的捕食性天敌名录119种,国内捕食性天敌名录29种;寄生性天敌主要包括寄生蜂和寄生蝇类,整理出国外报道的寄生性天敌名录47种,国内寄生性天敌名录53种.本文回顾了我国在美国白蛾天敌利用方面取得的阶段成果,并针对将来天敌复合体的应用和原产地天敌的引进提出了展望.     

饥饿程度对美国白蛾生长发育和繁殖的影响

不同龄期幼虫饥饿对美国白蛾Hyphantria cunea(Drury)生长发育和繁殖影响的研究结果表明:美国白蛾低龄(2龄)幼虫短时间的饥饿对其生长发育和繁殖的影响不明显;美国白蛾中龄(4龄)幼虫饥饿2,4,6d使美国白蛾的历期相应增长,存活率、化蛹率、羽化率、产卵量都相应降低,交配率与对照之间没有差异;老熟(6龄)幼虫短时间饥饿(4d)的存活率、羽化率、交配率、产卵量都稍有下降;长时间饥饿(12d)的老熟幼虫有70%左右因饥饿而提前化蛹,提前化蛹的蛹体外没有薄茧的包裹。提前化蛹的美国白蛾的羽化率、交配率均非常低,产卵量很少。     

Carotenoid-containing unilamellar liposomes loaded with glutathione: a model to study hydrophobic-hydrophilic antioxidant interaction

Unilamellar liposomes are used as a simple two-compartment model to study the interaction of antioxidants. The vesicle membrane can be loaded with lipophilic compounds such as carotenoids or tocopherols, and the aqueous core space with hydrophilic substances like glutathione (GSH) or ascorbate, mimicking the interphase between an aqueous compartment of a cell and its surrounding membrane.

Unilamellar liposomes were used to investigate the interaction of GSH with the carotenoids lutein, β-carotene and lycopene in preventing lipid peroxidation. Lipid peroxidation was initiated with 2,2′-azo-bis-[2,4-dimethylvaleronitrile] (AMVN). Malondialdehyde (MDA) formation was measured as an indicator of oxidation; additionally, the loss of GSH was followed. In liposomes without added antioxidant, MDA levels of 119 ± 6 nmol/mg phospholipid were detected after incubation with AMVN for 2 h at 37°C. Considerably lower levels of 57 ± 8 nmol MDA/mg phospholipid were found when the liposomal vesicles had been loaded with GSH. Upon incorporation of β-carotene, lycopene or lutein, the resistance of unilamellar liposomes towards lipid peroxidation was further modified. An optimal further protection was observed with 0.02 nmol β-carotene/mg phospholipid or 0.06 nmol lycopene/mg phospholipid. At higher levels both these carotenoids exhibited prooxidant effects. Lutein inhibited lipid peroxidation in a dose-dependent manner between 0.02 and 2.6 nmol/mg phospholipid. With increasing levels of lycopene and lutein the consumption of encapsulated GSH decreased moderately, and high levels of β-carotene led to a more pronounced loss of GSH.

The data demonstrate that interactions between GSH and carotenoids may improve resistance of biological membranes towards lipid peroxidation. Different carotenoids exhibit specific properties, and the level for optimal protection varies between the carotenoids.     

Effect of lead exposure on liver lipid peroxidative and antioxidant defense systems of protein-undernourished rats

The effect of the liver mitogen, lead nitrate [Pb(NO₃)₂], on protein-undernutrition-induced increased lipid peroxidation and reduced antioxidants levels was investigated in rats. Animals were divided into four groups: A, B, C, and D of five animals each. Animals in groups C and D were placed on a low-protein diet (5% casein) and animals in groups A and B were maintained on a normal diet (16% casein) for 14 wk and fed ad libitum. Animals in groups B and D were each given a single intravenous injection of Pb(NO₃)₂ (100 μmol/kg body weight) 72 h before sacrifice. The results confirm that protein undernutrition (PU) induced an increase in lipid peroxidation with concomitant reductions in catalase (CAT) activity, glutathione (GSH) level, and superoxide dismutase (SOD) activity. Lead (Pb) treatment, however, provoked increased lipid peroxidation, CAT activity, and GSH level but resulted in reduced SOD activity in both normal and PU-rats. These results suggest that Pb exacerbates liver lipid peroxidation in PU rats and suggests the involvement of free radicals in the pathogenesis of Pb poisoning. In addition, the results show that Pb affects well-fed and PU rats in similar ways but that the CAT activity of PU rats is more sensitive to the effect of Pb than that of normal rats.     

Effect of vitamin E and selenium supplementation of cockerel diets on glutathione peroxidase activity and lipid peroxidation susceptibility in sperm, testes, and liver

The phospholipids of avian spermatozoa are characterized by high proportions of arachidonic (20:4n-6) and docosatetraenoic (22:4n-6) fatty acids and are therefore sensitive to lipid peroxidation. α-Tocopherol and glutathione peroxidase [GSH-Px] are believed to be the primary components of the antioxidant system of the spermatozoa. The present study evaluates the effect of vitamin E and vitamin E plus Se supplementation of the cockerel diet on GSH-Px activity, vitamin E accumulation, and lipid peroxidation in the spermatozoa, testes, and liver. At the beginning of the experiment 75 Rhode Island Red cockerels were divided into five groups, kept in individual cages, and fed a wheat-barley-based ration balanced in all nutrients. Supplements fed to the different groups were as follows: vitamin E, 0, 20, 200, 20, and 200 mg/kg to groups 1–5, respectively, with groups 4 and 5 also receiving 0. 3 mg Se/kg. The vitamin E supplementation produced increased levels of α-tocopherol in semen, testes, and liver. The inclusion of the Se into the cock diet had a significant (P < 0.01) stimulating effect on GSH-Px activity in seminal plasma, spermatozoa, testes, and liver. The increased vitamin E concentration in the spermatozoa was associated with a reduction in their susceptibility to lipid peroxidation. Similarly, the increased GSH-Px activity provided enhanced protection against lipid peroxidation.