• Journal of Microbiology
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• 제39권2호
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• pp.142-145
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• 2001

Changes in the Activities of several antioxidant enzymes in transformed human dermal microvascular endothelial Cells (HMEC-1) by infection with the obligate intracellular bacterium Orientia tsutsugamushi, the causative agent of scrub typhus, were investigated. The activities of glucose-6-phosphate dehydrogenase, catalase, and glutathione peroxidase were significantly decreased in HMEC-1 cells infected with Ο. tsutsugamushi. However, the level of superoxide dismutase increased slightly. Furthermore, Increased levels of intracellular peroxide was observed in HMEC-1 during infection. These results support the hypothesis that cells infected by this intracellular bacterium experience oxidant-mediated injury that may eventually contribute to cell death.

• Nutrition Research and Practice
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• 제14권2호
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• pp.95-101
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• 2020

BACKGROUND/OBJECTIVES: Folate plays a critical role in DNA synthesis and methylation. Intracellular folate homeostasis is maintained by the enzymes folylpolyglutamate synthase (FPGS) and γ-glutamyl hydrolase (GGH). FPGS adds glutamate residues to folate upon its entry into the cell through a process known as polyglutamylation to enhance folate retention in the cell and to maintain a steady supply of utilizable folate derivatives for folate-dependent enzyme reactions. Thereafter, GGH catalyzes the hydrolysis of polyglutamylated folate into monoglutamylated folate, which can subsequently be exported from the cell. The objective of this review is to summarize the scientific evidence available on the effects of intracellular folate homeostasis-associated enzymes on cancer chemotherapy. METHODS: This review discusses the effects of FPGS and GGH on chemosensitivity to cancer chemotherapeutic agents such as antifolates, such as methotrexate, and 5-fluorouracil. RESULTS AND DISCUSSION: Polyglutamylated (anti)folates are better substrates for intracellular folate-dependent enzymes and retained for longer within cells. In addition to polyglutamylation of (anti)folates, FPGS and GGH modulate intracellular folate concentrations, which are an important determinant of chemosensitivity of cancer cells toward chemotherapeutic agents. Therefore, FPGS and GGH affect chemosensitivity to antifolates and 5-fluorouracil by altering intracellular retention status of antifolates and folate cofactors such as 5,10-methylenetetrahydrofolate, subsequently influencing the cytotoxic effects of 5-fluorouracil, respectively. Generally, high FPGS and/or low GGH activity is associated with increased chemosensitivity of cancer cells to methotrexate and 5-fluorouracil, while low FPGS and/or high GGH activity seems to correspond to resistance to these drugs. Further preclinical and clinical studies elucidating the pharmocogenetic ramifications of these enzyme-induced changes are warranted to provide a framework for developing rational, effective, safe, and customized chemotherapeutic practices.

• Journal of Plant Biology
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• 제32권4호
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• pp.285-292
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• 1989

The intracellular localizations of polyamines and their related enzymes were investigated from young spinach leaves. Polyamines were present in all parts of plant cells, both in the subcellular organelles and in the soluble fraction of cytoplasm, however, polyamines were mainly located in the cytosolic fraction. Most activities of L-arginine decarboxylase(ADC) and L-ornithine decarboxylase(ODC), two important enzymes of putrescine and polyamine biosynthesis, were detected in cytosol fraction, while in subcellular organelles the activities were very low. Activities of diamine oxidase(DAO) and polyamine oxidase(PAO), the catabolic enzyme of diamine and polyamine, were not detected in spinach leaves. It was suggested that polyamines and their related synthetic enzymes were located in the soluble fraction of cytoplasm.

• Applied Biological Chemistry
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• 제30권2호
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• pp.169-178
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• 1987

Kluyveromyces marxianus로 부터 inulase를 생산하고 정제하며 intra 및 extracellular inulase의 성질을 조사하였다. 본 균주는 stationary phase인 24시간째 intra 및 extracelullar enzyme의 생산이 최고에 달했으며 유기 질소원으로 YNB를 사용하고 배양 중 pH를 조절해 줌으로써 효소 생산을 향상시킬 수 있었다. 조효소는 DEAE-cellulose에 의해 intra 및 extracellular inulase 모두 2개의 fraction으로 분리되었고 각 fraction의 전기영동 양상은 비슷하여 주 band를 비롯 모두 3개의 glycoprotein band가 관찰되었으며 이중 주 band만 inulase 및 invertase activity를 보유하고 있었다. 정제 효소의 inulase 및 invertase의 최적 pH는 각각 5.0과 4.5였고 intra가 extracellular enzyme 에 비해 다소 넓은 범위의 pH에서 높은 활성을 나타내었다. 모든 fraction의 최적 온도는 inulase가 $40^{\circ}C$, invertase가 $50^{\circ}C$였으며 intracellular enzyme이 더 넓은 범위의 온도에서 안정하였고 열에 대한 안정성도 intracellular inulase가 extracellular inulase보다 높게 나타났다. Km value는 intra가 $16{\sim}19mM$, extracellular inulase가 $9{\sim}11mM$로써 extracellular inulase가 inulin에 대한 친화력이 더 높았으나 모두 exo-type의 inulase로 판명되었다.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.946-950
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• 2001

Slow-growing pathogenic mycobacterium species, including Mycobacterium bovis BCG, secrete a large amount of glutamine synthetase into culture media. Extracellular and intracellular glutamine synthetases were purified from M. bovis BCG. While the native molecular weights of both glutamine synthetases were estimated to be 370.2 kDa, those of the subunits were 61.7 kDa, indicating that the native forms were composed of 6 subunits. The enzymes showed a hhigh thermal stability and high degree of sequence similarity with the glutamine synthetase from M. tuberculosis in the N-terminal amino acid sequence. Western blotting analysis indicated that the antibodies prepared against both the extracellular and intracellular enzymes exhibited common antigen determinants.

• Archives of Pharmacal Research
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• 제13권4호
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• pp.298-305
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• 1990

Based on equal number of cells, supplementation of 10$^{-6}$ M cadimium highly simulated the intracellular amylase. GCT, LDH as well as the glucose and erea content of E carotovora var, carotovaro cells. This was coupled with initiation of highly active GOT, CPK as well as accumulation of cholesterol in the cells. Lanthanum was less active and unable to initiate COT or CPK. Nickel was almost without effect though reduced LDH activity without initiating either enzyme or cholesterol production. Similar stiulations and/or initiations were observed, though to variable extents, when the same concentration of the three elements were supplied to E. carotovora var, citullis or E. toxica. The highest yield of amylase, GPT, GGT or glucose was obtained when E. carotovora var. carotovora was supplemented with Cd + Ni. The highest urea level was recorded in Erwinia carotovara var, cirullis, amended with Cd + La.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.422-430
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• 2000

Mechanism of lignin biodegradation caused by basidiomycetes and the history of lignin biodegradation studies were briefly reviewed. The important roles of fungal extracellular ligninolytic enzymes such as lignin and manganese peroxidases (LiP and MnP) were also summarized. These enzymes were unique in their catalytic mechanisms and substrate specificities. Either LiP or MnP system is capable of oxidizing a variety of aromatic substrates via a one-electron oxidation. Extracellular fungal system for aromatic degradation is non-specific, which recently attracts many people working a bioremediation field. On the other hand, an intracellular degradation system for aromatic compounds is rather specific in the fungal cell. Structurally similar compounds were prepared and metabolized, indicating that an intracellular degradation strategy consisted of the cellular systems for substrate recognition and metabolic response. It was assumed that lignin-degrading fungi might be needed to develop multiple metabolic pathways for a variety of aromatic compounds caused by the action of non-specific ligninolytic enzymes on lignin. Our recent results on chemical stress responsible factors analyzed using mRNA differential display techniques were also mentioned.

• Journal of Radiation Protection and Research
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• 제2권1호
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• pp.31-37
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• 1977

Inactivation of the glutamic acid dehydrogenase and glucose-6-phosphate dehydrogenase enzyme-molecules in the Ehrlich ascites tumor cells of the mouse were studied. The above mentioned intracellular enzymemolecules were irradiated by the X-ray radiation under the condition of 65 kV, I Amp. under the atmosphere of nitrogen gases and by $4^{\circ}C$. Thereby, irradiation doses were 580 KR/min($error:{\pm}3%$). After irradiation, the cell homogentes were prepared through liquid air techniquese. There after, the activities of the enzymes were measured with photometric method given by O. Warburg and W. Christian. The dose effect curves of the activities of the two enzymes by the X-ray irradiation showed both exponential and the inactivation doses were $6,5.10^{0}\;and\;5,0.10^{6}$ R respectively. These results showed one side that the inactivation process of the intracelluar enzymemolecules was one hit reaction after target theory, and the other side that this inactivation process could not be the primary causes of the death through X-ray irradiation of the vertebrate animals, because of the high resistance of the intracellular protein molecules against X-ray irradiation. The one hit reaction by the inactivation process of the irradiated intracellular enzymemolecules was discussed.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과학회 2002년도 제54회 춘계심포지움 - 우유와 국민건강
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• pp.45-55
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• 2002

Recent developments in the application of molecular biology to food grade lactic acid bacteria (LAB) have shown that it could be feasible to engineer metabolic pathways to either enhance specific metabolic fluxes or to divert metabolites for the production of different or new end products. This engineering requires detailed knowledge of enzymes involved in metabolism and regulation within the targeted organism but little works have been done in this area. During biochemical and molecular characterisation of lactic bacterial enzymes, some of probiotic Lactobacillus and Bifidobacterium species were found to be very useful for food, nutraceutical and pharmaceutical industries. The enzymes are usually intracellular and the yields are very low to be useful for industrial applications. Among many enzymes and proteins of lactic bacteria studied, some of our gene cloning achievements have contributed to overproduction of lactic bacterial enzymes such as peptidases, esterases, lactases, bile salt hydrolases and linoleate isomerases for foods and nutraceuticals.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.21-27
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• 2012

Ground seawater in the east area of the volcanic Jeju Island contains abundant minerals. We investigated the metabolic activity of electrodialyzed, desalted ground seawater (EDSW) from Jeju in both cultured cells and animals. The addition of EDSW to the culture medium (up to 20%, v/v) reduced the leakage of lactate dehydrogenase and increased MTT activity in CHO-IR cells. EDSW (10%) promoted insulin-induced glucose consumption in L6 muscle cells as well as the activities of the liver ethanol-metabolizing enzymes, alcohol dehydrogenase and aldehyde dehydrogenase. Moreover, EDSW suppressed palmitate-induced intracellular fat accumulation in human hepatoma $HepG_2$ cells. Activities of AMP-stimulated protein kinase and acetyl CoA carboxylase, enzymes that modulate fat metabolism, were altered by EDSW in $HepG_2$ cells toward the suppression of intracellular lipid accumulation. EDSW also suppressed hepatic fat accumulation induced by a high-fat diet in mice. Taken together, EDSW showed beneficial metabolic effects, including the enhancement of ethanol metabolism and insulin-induced glucose consumption, and the suppression of intrahepatic fat accumulation.