• Journal of Plant Biology
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• 제25권2호
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• pp.73-81
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• 1982

The changes in activities of glyoxysomal and peroxisomal enzymes during the transition from fat degradation to photosynthesis were investigated with the cotyledns of rape (Brassica napus L.) seedlings. The development and disappearance of glyoxysomal enzyme (isocitrate lyase, EC 4.1.3.1; malate dehydrogenase, EC 1.1.1.37; catalase, EC 1.11.1.6) activities took place independently of light. It is concluded that the mobilization of storage fat is independent of photomorphogenesis. During early periods of development in the dark of light (days 1 through 3), the glyoxysomal enzyme activities were relatively high and the enzyme activities rose to a peak at 3rd day after sowing. Thereafter, the activities decreased gradually. While glyoxysomal enzyme activities were dropping, the peroxisomal enzyme (glycolate oxidase, EC 1.1.3.1) activities were increasing rapidly during the transition period in the light. Moreover, the changes of enzyme activities of the common microbody marker, catalase, indicated both functional patterns. The enzyme patterns in rape cotyledons indicate that the glyoxysomal function of microbodies is replaced by the peroxisomal function of these organelles during the transition from fat degradation to photosynthesis.

• 대한화학회지
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• 제37권12호
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• pp.1068-1075
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• 1993

토마토(Lycopersicum esculentum)를 파종하여 1년간 성장시키면서 성장기간에 따른 잎과 뿌리의 catalase 활성 변화를 측정하였다. 뿌리에 있어서의 catalase 활성은 잎의 경우에 비해 전반적으로 매우 미약하였다. 반면에 잎의 catalase 활성은 매우 현저한 변화 양상을 나타냈는데 주로 peroxisomal 분획에 존재하였고 특히 발아 후 2주 이내의 발아초기에 76 ${\mu}mol$/ml/min의 최고 활성은 기점으로 하여 급격히 감소했다가 성장기 4 ∼ 5 개월에 즈음하여 상당히 증가된 활성을 보였으며 11 ∼ 12개월째 노화기에 가장 저조한 활성을 보였다. 이와 같이 성장시기에 따라서 변화하는 catalase 활성에 영향을 미치는 인자로서 첫째 발아기에는 glyoxylate cycle과 $\beta$-oxidation이 일어나는 glyoxisomal 반응 그리고 둘째 발아기 이후에는 광합성 반응이 각각 해당시기에 $H_2O_2$를 발생시키는 반응으로 작용할 것으로 간주된다. 이 외에도 NADPH는 불활성화된 catalase(compound II)를 다시 활성화시켜 해로운 기질인 $H_2O_2$로부터 catalase 보호제로서의 역할을 함으로써 토마토의 생장기간 전체에 걸쳐 작용하는 것으로 나타났다.

• Journal of Nutrition and Health
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• 제26권7호
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• pp.887-898
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• 1993

In order to determine the effect of iron depletion and subsequent supplementation on the muscle capacity for peroxisomal (PO) and mitochondrial(MO) $\beta$-oxidation during high fat feeding, weanling rats were fed a 44% (HF) or 2.5% (LF) fat diet with (+Fe) or without (-Fe) iron for 6 or 9 weeks. After 1 week rats fed HF+Fe or HF-Fe had 50-100% more PO and MO in heart, soleus, psoas and gastrocnemius than did rats fed low fat, but after 3 weeks rats fed HF-Fe had lower muscle PO and MO. In muscles of iron depleted rats PO and MO were not increased by supplementation with iron for 3 weeks. After 6 weeks MO and PO in skeletal muscles of rats fed HF+Fe were lower than after 3 weeks. It is concluded that adequate iron is necessary for miaximum response of muscle PO and MO to high fat feeding. However, after 6 weeks both PO and MO have returned to levels similar to those of rats fed low fat diets, hence, the elevated catalase activities seen at this time do not reflect peroxisomal $\beta$-oxidation.

• Journal of Nutrition and Health
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• 제34권8호
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• pp.858-864
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• 2001

The study was designed to observe an antioxidant activities of conjugated linoleic acid(CLA) in rat liver by determining the activities of antioxidative enzymes(superoxide dismutase, glutathione peroxidase, catalase) and the levels of tocopherol and thiobarbituric acid reactive substance(TBARS). Male Sprague Dawley rats at weeks-old were divided into groups according to the types of dietary fat(beef tallow and fish oil) and then each group was subdivided into groups depending on CLA supplement. All rats were fed experimental diet containing 12% total fat including 1% CLA by weight for 30 weeks. CLA supplemented to beef tallow diet did not have significant effect on the level of TBARS and tocopherol. The level of TBARS was significantly increased in fish oil diet(highly unsaturated fat diet), but its level was significantly reduced by increasing SOD and GSH-Px activities when CLA was supplemented to fish oil diet so that CLA showed a sparing action of tocopherol in tissue. CLA did not have significant effect on peroxisomal catalase activities, but its activity was significantly increased when TBARS production was high in the fish oil diet. CLA could be incorporated into phospholipid of microsomal membrane, and interfered the conversions of C18 : 0 into C18 : 1 and C18 : 2 into C20 : 4 in liver. In conclusion, CLA had an antioxidant activities depending on the type of fat in diet. Therefore, it could be recommended to use CLA when highly unsaturated fat was used in meal preparation.

• Journal of Plant Biology
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• 제27권4호
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• pp.241-251
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• 1984

The present study investigated the effects of triacontanol (TRIA) on plant growth and peroxisomal enzyme activities in radish seedlings. The optimum concentration of TRIA with respect to radish seedling bioassay was decided to 1.0mg $1^{-1}$. In comparison to untreated controls (including Tween 20 treatment), 1.0mg $1^{-1}$ TRIA treatment caused an increase in seed germination rate and root growth, but no stimulation in hypocotyl growth. Chlorophyll accumulation in cotyledon during carly development stage increased rapidly, and degradation of chlorophyll in later stage due to the cotyledon senesence was noticeably retarded. Increase of soluble protein content in cotyledon at early period of development was observed. Isocitrate lyase and catalase activity was not significantly different in both the treated and the untreated plants. But, glycolate oxidase activity was inhibited by TRIA down to 20% against controls. Also, the increase of the activity of peroxidase, a leaf-senescence marker enzyme, was continuously retarded over control for 8 days of development. Based on above results, TRIA was found to be active in both the growth and the peroxisomal enzyme activities of radish seedlings.

• Journal of Plant Biology
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• 제31권3호
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• pp.197-203
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• 1988

The rates of photorespiration and total CO2 fixation depending on leaf ages of spinach (Spinacia oleracea L.) were investigated. Metabolic rates of glycolate and glyoxylate in isolated peroxisomes were also measured. The rate of photorespiration and total CO2 fixation ability increased with the maturing of leaf, but decreased with senescence. Activities of enzymes involved in the peroxisomal photorespiratory pathway such as catalase, glycolate oxidase, NADH-glyoxylate reductase and glutamate-glyoxylate transaminase were highest in the mature leaf, but also decreased with aging of leaf. Glutamate-glyxolate transaminase activity significantly decreased with senescence, especially. the metabolic rate of glycolate was observed to be lower than that of glyoxylate in isolated peroxisomes. Glycolate seemed to be metabolized mainly to glycine, however, it also oxidized to CO2 when glycolate was supplied as a substrate for glycine synthesis instead of glyoxylate. The conversion rates of glycolate and glyxylate into CO2 increased with the senescence of leaves.

• Molecules and Cells
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• 제38권2호
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• pp.187-194
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• 2015

Thioredoxin (TRX) is a disulfide reductase present ubiquitously in all taxa and plays an important role as a regulator of cellular redox state. Recently, a redox-independent, chaperone function has also been reported for some thioredoxins. We previously identified nodulin-35, the subunit of soybean uricase, as an interacting target of a cytosolic soybean thioredoxin, GmTRX. Here we report the further characterization of the interaction, which turns out to be independent of the disulfide reductase function and results in the co-localization of GmTRX and nodulin-35 in peroxisomes, suggesting a possible function of GmTRX in peroxisomes. In addition, the chaperone function of GmTRX was demonstrated in in vitro molecular chaperone activity assays including the thermal denaturation assay and malate dehydrogenase aggregation assay. Our results demonstrate that the target of GmTRX is not only confined to the nodulin-35, but many other peroxisomal proteins, including catalase (AtCAT), transthyretin-like protein 1 (AtTTL1), and acyl-coenzyme A oxidase 4 (AtACX4), also interact with the GmTRX. Together with an increased uricase activity of nodulin-35 and reduced ROS accumulation observed in the presence of GmTRX in our results, especially under heat shock and oxidative stress conditions, it appears that GmTRX represents a novel thioredoxin that is co-localized to the peroxisomes, possibly providing functional integrity to peroxisomal proteins.

• 생명과학회지
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• 제33권8호
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• pp.651-662
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• 2023

마이크로바디로 알려진 퍼옥시좀은 대부분의 진핵세포에서 흔히 발견되는 형태학적으로 유사한 세포내 소기관의 한 종류이다. 크기는 직경이 0.2~1.8 ㎛이고 단일 막으로 싸여 있다. 매질은 일반적으로 미세한 입자이지만 때로는 결정체 또는 섬유질의 형태가 관찰된다. 이들은 특징적으로 과산화수소(H₂O₂)를 생성하는 산화효소를 가지고 있으며 효소 카탈레이스를 함유하여 세포 소기관 내에서 생성되는 유독한 H₂O₂를 제거한다. 퍼옥시좀은 형태학적으로나 물질대사의 측면에서 진핵세포의 세포내 소기관으로써 대단히 역동적이다. 특히, 식물의 퍼옥시 좀은 β-산화, 글라이옥실산 회로 및 광호흡 등을 포함한 수많은 대사 과정과 관련이 있다. 또한, 식물 퍼옥시좀은 중요한 식물 호르몬인 옥신, 살리실산 및 자스몬산의 합성과 스트레스에 대한 반응 및 발달에 관여한다. 지난 20년 동안 진핵생물의 퍼옥시좀 발생에 관한 연구는 동물과 효모에서 상당한 진전을 이루었다. 정교한 분자생물학 기술의 발전과 유전체학의 광범위 활용으로 대부분의 퍼옥시좀 관련 유전자와 단백질(peroxin, PEX)이 확인되었다. 또한, 최근에 단백체 연구의 적용은 퍼옥시좀 단백질의 표적화, 조절 및 분해에 대한 이해와 함께 식물 퍼옥시좀의 발생에 대한 기초 정보를 얻을 수 있게 되었다. 이와 같은 퍼옥시좀 발달에 관한 연구에 커다란 진전에도 불구하고, 퍼옥시좀이 ER에서 유래하여 조립되고 분열하는 과정에 대하여 여전히 많은 의문이 남아 있다. 퍼옥시좀은 식물 발달의 여러 측면에서 역동적인 역할을 수행하며, 이 논문에서는 식물 퍼옥시좀의 기능, 발생 및 역동성에 대한 이해를 위하여 그 동안의 연구 동향에 중점을 두었다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1162-1167
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• 2004

The present study was designed to define whether dietary conjugated linoleic acid (CLA) could affect antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and glutathione S transferase (GST), and the level of malondialdehyde (MDA), a marker of lipid peroxidation, in the small intestine and liver from broiler chickens. A total of twenty-four 3 wk-old male broiler chickens were assigned to three dietary treatments (1.5% corn oil, 0.75% corn oil plus 0.75% CLA, and 1.5% CLA, isocalorically), and fed a grower-finisher diet from 22 to 35 days. In the small intestinal mucosae, the specific activities of SOD, GSH-Px, CAT, and GST, and the level of MDA were not substantially influenced by dietary CLA. In the liver, the specific activities of SOD, GSH-Px, and GST, and the level of MDA were also unaffected by dietary CLA at the level of either 0.75% or 1.5% compared with corn oil at the level of 1.5%. However, the broiler chickens fed the diet containing 1.5% CLA resulted in a significant increase in peroxisomal CAT activity and a marked decrease in total lipid and non-esterified fatty acids (NEFA) from liver tissues compared with those fed the diet containing 1.5% corn oil. In conclusion, ability of CLA to increase hepatic CAT activity suggest that dietary CLA may affect, at least in part, antioxidant defense system as well as lipid metabolism in the liver of broiler chickens.