• 한국식품영양학회지
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• 제9권1호
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• pp.85-91
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• 1996

B-amylase(EC 3.2.1.2) was isolated from the root of arrowroot(Peuria thunbergiana Bentham) with distilled water and then fractionated with ammonium sulfate. Crude extract was partially purified by ion exchange chromatography and gel filtration. The enzymatic properties of partially purified $\beta$-amylase were as follows, the enzyme was fractionated with ammonium sulfate between 0.2 and 0.4 saturation, and showed the typical reaction properties of B-amylase producing only maltose from starch. Optinum pH and temperature were pH 6.5, $50^{\circ}C$ respectively. The activity of the enzyme had proportional relations with enzyme protein concentration below 4mg, and had Michaelis constant of 66.7mg% for soluble starch. The enzyme was inhibited by some metal louts such as silver, cadmium, mercury, aluminum, iron and copper.

• Journal of Plant Biotechnology
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• 제6권4호
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• pp.259-264
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• 2004

The present study describes the ameliorating effect of $Ca^{++}\;on\;Cd^{++}$ toxicity on the germination, early growth of mungbean seedlings, nitrogen assimilation enzyme. s-nitrate reductase (NR), nitrite reductase (NIR), anti-oxidant enzymes (POD, CAT and SOD) and on the accumulation of hydrogen peroxide and sulphydryls. $Cd^{++}$ inhibited seed germination and root and shoot length of seedlings. While NR activity was down- regulated, the activities of NIR, POD and SOD were up- regulated with $Cd^{++}$ treatment. $Cd^{++}$ treatment also increased the accumulation of sulphydryls and peroxides, which is reflective of increased thiol rich proteins and oxidative stress. $Ca^{++}$ reversed the toxic effects of $Cd^{++}$ on germination and on early growth of seedlings as well as on the enzyme activities, which were in turn differentially inhibited with a combined treatment with calcium specific chelator EGTA. The results indicate that the external application of $Ca^{++}$ may increase the tolerance capacity of plants to environmental pollutants by both up and down regulating metabolic activities. Abbreviations: $Cd^{++}= cadmium,\;Ca^{++} = calcium$, NR= nitrate reductase, NIR=nitrite reductase, POD = peroxidse, SOD= superoxide dismutase, CAT= catalase, EGTA= ethylene glycol-bis( $\beta-aminoethyl ether$)-N,N,N,N-tetraacetic acid.

• Journal of Nutrition and Health
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• 제33권7호
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• pp.725-732
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• 2000

The purpose of this study was to investigate the effects of green tea catechin on renal dysfunction and blood presure change in chronic cadmium poisoned rats. Sprague-Dawley male rats weighing 100$\pm$10g were randomly assigned to one normal group and three cadmium poisoned groups. Cadmium groups were classified to catechin free diet(Cd-0C group) 0.25% catechin diet(Cd-0.25C group) and 0.5% catechin diet(Cd-0.5C group) according to the levels of catechin supplement. Animals were raids for 20weeks. Cadmium were supplied as drinking water of 50ppm Cd2+ Morphological changes shown through a light microscope and an electro-microscope revealed the mitochondria and tubule epithelial cell edema in Cd -0C group but they were alleviated in catechin supplementation. The urinary $\beta$2-microglobulin that measured to observe the glomerular injury were higher in Cd-poisoned groups than in normal group but they was lowered by catechin supplementation. Glomerular filtration ratios(GFR) in Cd-poisoned groups were significantly lower than in normal group but that of catechin supplementation group was similar to normal group. This suggested that catechin protected the kidney from the functional damage. Angiotensin converting enzyme(ACE) activity and blood pressure(BP) in Cd-poisoned groups were significantly higher than in normal group. Heart rate was tended to increase in Cd-poisoned groups. The results indicate that green tea catechin supplementation on chronic cadmium-poisoned rats normalized the renal dysfunction and blood pressure system.

• 대한수의학회지
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• 제37권2호
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• pp.383-388
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• 1997

카드뮴이 마우스의 효소활성에 미치는 영향을 평가하고자 BALB/c 마우스를 대상으로 0, 25, 50, 100 및 200 ppm의 $CdCl_2$가 첨가된 음료를 7주동안 자유급식한 후 간 및 신장에서 카드뮴(Cd)의 축적정도 및 효소(LDH 및 SOD)활성 변화를 조사하여 다음과 같은 결과를 얻었다. 1. 간 및 신장에서의 Cd축적도는 투여량이 증가될 수록 높았으며 특히 신장에서 더욱 높았다. 2. 간장과 신장의 lactate dehydrogenase(LDH)활성치는 신장의 경우 농도가 증가할 수록 활성치도 증가(25 ppm ; p<0.05, 50, 100 및 200 ppm; p<0.01)하는 경향을 보였으나 간에서는 100 ppm까지는 농도에 비례하여 활성치도 증가(50 및 100 ppm; p<0.05)하였다가 200ppm 투여군에서는 25 ppm 투여군 수준으로 감소되었다. 3. Superoxide dismutase(SOD)활성은 25 ppm 투여군의 간장에서 유의한 상승치(p<0.05)를 보인 것을 제외하고는 대조군의 간 및 신장의 활성치와 유사한 결과를 보였다. 이상의 결과는 카드뮴이 농도에 따라서 생체내의 LDH 및 SOD와 같은 효소계의 활성에 영향을 미칠 수 있음을 시사한다.

• 한국환경보건학회지
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• 제23권4호
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• pp.121-126
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• 1997

Peroxidase as one of the organic enzyme catalyst is useful for the oxidation treatment of various aromatic compounds such as phenols. The peroxidase content of Oenanthe javanica was 24.85 unit/g-fw in leaf, 5.74 unit/g-fw in stem, and 34.69 unit/g-fw in root respectively. The crude peroxidase extracted from Oenanthe javanka can be kept under low temperature (-70$\circ$C) condition for 6 months with the maximum 1% activity reduction. The optimum conditions of removal for 100 ppm phenol was pH 6, hydrogen peroxide 3.5 mM, peroxidase activity 8 unit/ml, temperature 20$\circ$C respectively. In the wide range of concentration from 50 ppm to 750 ppm phenol reveals average 54% removal rate under the same peroxidase activity (8 unit/ml) and different amount of hydrogen peroxide proportional to phenol concentration. Especially at the concentration of 100 ppm the maximum phenol removal rate was 72%.

• Journal of Ecology and Environment
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• 제34권4호
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• pp.393-400
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• 2011

The effects of the ectomycorrhizal fungus Pisolithus tinctorius and cadmium (Cd) on physiological properties and Cd uptake by Populus alba ${\times}$ glandulosa was investigated under greenhouse conditions. Cd treatment decreased the photosynthetic rate ($P_N$) of both non-mycorrhizal (NM) plants (16.3%) and ectomycorrhizal (ECM) plants (11.5%). In addition, the reduction in total dry weight by Cd treatment was greater in ECM plants (24.3%) than that in NM plants (17.6%). Mycorrhizal infection increased the $P_N$ and transpiration rate in both control and Cd-treated plants. Cd treatment increased superoxide dismutase (SOD) activity and decreased glutathione reductase activity, and the increase of SOD activity by Cd treatment was greater in NM plants (40.3%) than that in ECM plants (3.7%). Thiol content increased in both NM and ECM plants treated with Cd solution, and the increase in thiol content in NM plants (43.9%) was greater than that of ECM plants (15.6%). Cd uptake in the leaves, stems, and roots of ECM plants was 69.9%, 167.2% and 72.8%, respectively, higher than in the NM plants. However, the increase in Cd uptake ability of ECM plants resulted in a reduction in dry weight.

• 한국식품영양과학회지
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• 제23권4호
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• pp.574-580
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• 1994

식이성 아연의 급여 수준이 카드뮴을 투여한 흰주의 체내대사에 미치는 영향을 구명하고자 간손상 정도의 지표로 쓰이는 효소와 간해독 과정에 관여하는 효소의 활성을 생화학적 측면에서 관찰한 결과는 다음과 같다. 식이성 아연결핍군의 체중증가량, 식이섭취량 및 식이효율은 유의적으로 감소하였으며, 과잉군에서는 유의적이지는 않았으나 증가하는 경향이었다. 카드뮴은 체중 및 식이섭취량에 유의적인 영향을 미치지는 않았다. 간조직중의 GSH-Px, GST 및 catalase 활성은 식이성 아연 과잉과 결핍군 모두에서 감소하였는데, 특히 결핍시의 활성 감도는 유의적이었다. 카드뮴은 GSH-Px와 GST의 활성을 유의적으로 감소시켰으며, GST는 아연 과잉시 활성 감도 정도가 결핍군에 비하여 다소 억제된 것으로 나타났다. Catalase 활성은 카드뮴 투여시 아연결핍군에서 유의적인 감소가 있었으나 과잉군과 정상군에서는 그 감소가 유의적이지는 않았다. 간조직중의 LPO 함량은 식이성 아연 결핍시 유의적인 증가를 나타내었으며, 카드뮴은 아연 결핍보다 과잉시 LPO 생성이 지연되는 것으로 나타났다. GSH 함량은 결핍과 과잉군 모두 정상군에 비하여 유의적으로 감소를 나타내었으며, 카드뮴은 아연 결핍과 정상군의 GSH 함량을 유의적으로 감소시켰는데 정상군의 감소 정도가 가장 크게 나타났다. 혈청 AST와 ALT 활성은 정상군에 비하여 아연 결핍과 과잉시 증가하였으며, 특히 결핍시에 증가 정도가 크게 나타났다. 카드뮴은 AST 활성을 현저하게 증가시켰으나 각 군간에 유의성은 나타나지 않았다. 또한 카드뮴은 아연결핍군과의 정상군의 ALT의 활성을 유의적으로 증가시켰으며 과잉군의 경우 결핍군에 비하여 그 증가가 억제되었다. LDH 활성은 아연 공급수준에 따른 차이가 나타나지 않았으나, 카드뮴 투여는 그 활성을 유의적으로 증가시켰으며 아연과징군이 결핍군 보다 활성을 억제하는 것으로 나타났다. ALP는 아연결핍군의 활성 감소가 유의적이었으며, 카드뮴은 각 군의 활성을 유의적으로 증가시켰으나 아연 공급수준이 높아질수록 그 활성이 감소하였다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.62-72
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• 2002

This study has investigated the biosynthesis and function of the heavy metal binding peptides, the phytochelatins, in plants. PCs are synthesised enzymatically from glutathione by the enzyme PC synthase in the presence of heavy metal ions. Using Arabidopsis thaliana as a model organism cadmium-sensitive, phytochelatin-deficient mutants have been isolated and characterised in previous studies. The cadl mutants have wildtype levels of glutathione, are PC deficient and lack PC synthase activity. Thus, the CADl gene has been proposed to encode PC synthase. The CADl gene was isolated by a positional cloning strategy The gene was mapped and a candidate identified. Each of four cadl mutants had a single base pair change in the candidate gene and the cadmium-sensitive, cadl phenotype was complemented by the candidate gene. This demonstrated the CADl gene had been cloned. A homologous gene in the fission yeast, Schizosaccharomyces pombe was identified through database searches. A targeted-deletion mutation of this gene was constructed and the mutant, like cadl mutants of Arabidopsis, was cadmium-sensitive and PC-deficient. A comparison of the redicted amino acid sequences reveals a highly conserved N-terminal region Presumed to be the catalytic domain and a variable C-terminal region containing multiple Cys residues proposed to be involved in activation of the enzyme by metal ions. Similar genes were also identified in animal species. The Arabidopsis CADl/AtPCSl and S. pombe SpbPCS genes were expressed in E. coli and were shown to be sufficient for glutathione-dependent, heavy metal activate PC synthesis in vitro, thus demonstrating these genes encode PC synthase enzymes. Using RT-PCR, AtPCSl expression appeared to be independent of Cd exposure. However, at higher levels of Cd exposure a AtPCSl-CUS reporter gene construct appeared to be more highly expressed. Using the reporter gene construct, AtPCSl was expressed most tissues. Expression appeared to be greater in younger tissues and same higher levels of expression was observed in some regions, including carpels and the base of siliques. AtPCS2 was a functional gene encoding an active PC synthase. However, its Pattern of expression and the phenotype of a mutant (or antisense line) have not been determined. Assuming the gene is functional then it has clearly been maintained through evolution and must provide some selective advantage. This implies that, at least in some cells or tissue, it is likely to be the dominant PC synthase expressed. This remains to be determined

• Nutritional Sciences
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• 제9권1호
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• pp.20-28
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• 2006

Aryl sulfotransferase (AST) IV is a liver enzyme involved in detoxication and has been shown to be susceptible to down regulation by a number of hepatotoxic xenobiotics. Studies presented here to investigate the ability of biological and non-biological divalent metal cations on AST IV activity showed that AST IV was strongly inhibited following in vitro or in vivo exposure to. Zn ( II ), Co ( II ) or Cd ( II ). It was found that $0.025\sim$2.5 uM of these metal ions were sufficient to cause $50\%$ of inhibition in vitro in purified AST IV and $0.25\sim$25 uM of these metal ions in liver cytosolic fractions. For the in vivo study, 1,000 mg Cu ( II )/kg, 2,000 mg Zn ( II )/kg or 250 mg Cd( II )/kg was added to individual diets and administered to three (3) group; of mts over a 7 week period The Co ( II )-supplemented diet produced no apparent change in rat growth rate and resulted in 30-fold increase in liver cytotolic Cu ( II ) levels, suggesting that elevated levels of Cu ( II ) ion in the liver were responsible for the loss of AST IV activity. In contrast, the Zn ( II )-supplemented diet caused a decrease in rat growth rates and resulted in zero increase in liver Zn ( II ) levels, which suggested an indirect inhibition mechanism was caused by Zn ( II ) in the liver. Rats were fed the Cd-supplemented diet also displayed a decrease in growth rate with little or no change in liver Cu ( II ) or Zn ( II ) levels. When the liver cytosols of mts from the metal ion diets were immunochemically analyzed for the AST IV and albumin contents, no significant changes were observed in albumin levels. However, AST IV contents in the cytosols of mts fed the Zn ( II )-supplemented diets showed a slight decrease in amount These results showed that AST IV activity in vitro and in vivo can be inhibited by Co ( II ), Zn ( II ), and Cd ( II ) by apparently different mechanisms. The immediate response to a Zn injection showed a decrease in AST IV activity but not in the AST IV content in liver cytosol. These mechanisms appeared to involve direct actions of the metal ion on AST IV activity and indirect actions affecting AST IV amount.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1557-1567
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• 2012

Glutathione reductase (GR, E.C. 1.6.4.2) is an important enzyme that reduces glutathione disulfide (GSSG) to a sulfydryl form (GSH) in the presence of an NADPH-dependent system. This is a critical antioxidant mechanism. Owing to the significance of GR, this enzyme has been examined in a number of animals, plants, and microbes. We performed a study to evaluate the molecular properties of GR (OsGR) from rice (Oryza sativa). To determine whether heterologous expression of OsGR can reduce the deleterious effects of unfavorable abiotic conditions, we constructed a transgenic Saccharomyces cerevisiae strain expressing the GR gene cloned into the yeast expression vector p426GPD. OsGR expression was confirmed by a semiquantitative reverse transcriptase polymerase chain reaction (semiquantitative RT-PCR) assay, Western-blotting, and a test for enzyme activity. OsGR expression increased the ability of the yeast cells to adapt and recover from $H_2O_2$-induced oxidative stress and various stimuli including heat shock and exposure to menadione, heavy metals (iron, zinc, copper, and cadmium), sodium dodecyl sulfate (SDS), ethanol, and sulfuric acid. However, augmented OsGR expression did not affect the yeast fermentation capacity owing to reduction of OsGR by multiple factors produced during the fermentation process. These results suggest that ectopic OsGR expression conferred acquired tolerance by improving cellular homeostasis and resistance against different stresses in the genetically modified yeast strain, but did not affect fermentation ability.