• 한국식품영양과학회지
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• 제23권6호
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• pp.964-972
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• 1994

The 4.3-kb gene coding for L-lactate dehydrogenase of Bacillus stearothermophilus has been subcloned and expressed in E. coli cells. The enzyme was purified 200-fold with 25% yield by heat treatment , DEAE-Sephadex, and NAD++ -Sepharose CL-4B affinity chromatography followed by gel filtration through Sephadex G-200 . The molecular weight of the purfied enzyme was estimated to be about 35, 000 and 140, 000 on SDS-polyacrylamide gel electrophoresis and gel filtration, respectively. indicating that the enzyme is composed of four identical subunits. THe enzyme for pyruvate reduction and lactate oxdiation was stable at 60 and 75$^{\circ}C$ for 30 min, and the optimal temperatures for both reactions were 60 and 7$0^{\circ}C$, respectively. The enzyme had an optimal pH at 5.5 and 8.5 in pyruvate reduction and lactate oxidation, respectively. The pH stability of enzyme of pyruvate reduction was table between pH 5 and 7. more than 90% of enzyme activity was lost at 1mM FeSO4 and p-chloromercuribonzoate. The maximal activation of the enzyme was obtained with 0.8mM fructose 1, 6-bisphosphate.

• BMB Reports
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• 제40권2호
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• pp.172-179
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• 2007

PCR-mediated recombination describes the process of in vitro chimera formation from related template sequences present in a single PCR amplification. The high levels of genetic redundancy in eukaryotic genomes should make recombination artifacts occur readily. However, few evolutionary biologists adequately consider this phenomenon when studying gene lineages. The cytosolic glyceraldehyde-3-phosphate dehydrogenase gene (GapC), which encodes a NADP-dependent nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase in the cytosol, is a classical lowcopy nuclear gene marker and is commonly used in molecular evolutionary studies. Here, we report on the occurrence of PCR-mediated recombination in the GapC gene family of Hibiscus tiliaceus. The study suggests that recombinant areas appear to be correlated with DNA template secondary structures. Our observations highlight that recombination artifacts should be considered when studying specific and allelic phylogenies. The authors suggest that nested PCR be used to suppress PCRmediated recombination.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2002년도 춘계학술발표대회 및 심포지움
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• pp.215-215
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• 2002

Catalytic subunit of pyruvate dehydrogenase phosphatase (PDPc) has been suggested to have three major funational domains such as dihydrplipoamide adetyltransferase(E2)-binding domain, regulatory subunit of PDP(PDP)r-binding domain, and calcium-binding domain. In order to identify functional domains, recombinant catalytic subunit of pyruvate dehydrogenase phosphatase(rPDPc) was expressed in E. coli JM101 and purified to near homogeneity using the unique property of PDPc: PDPc binds to the inner lipoyl domain (L2) of E2 of ppyruvate dehydrogenase complex (PDC) in the presence of Ca+2, not under EGTA. PDPc was limited-proteolysed by typsin, chymotypsin, Arg-C, and elastase at pH 7.0 and 30C and N-terminal analysis of the fragments was done. Chymotrypsin, trypsin, and elastase made two major fragments: N-terminal large fragment, approx. 50kD and C-terminal small fragment, approx.10 kDa. Arg-C made three major fragments: N-terminal fragment, approx. 35kD, and central fragment, approx. 15 kD, and C-terminal fragment, approx. 10 kD. This study strongly suggest that PDPc consists of three major functional domains. However, further study should be necessary to identify the functional role.

• 동의생리병리학회지
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• 제18권6호
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• pp.1723-1727
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• 2004

We investigated the activity and stability of alcohol dehydrogenase from horse liver (HLADH) under the electric stimulation. The activity and stability of alcohol dehydrogenase depended on electric output voltaqe, stimulation time, pulse duration and pulse interval, and temperature. HLADH retained about 23% of its activity in buffer but 78% in 10% trehalose solution under electric stimulation with 10V, 10min, The stabilizing of enzymes against electric stimulation by stabilizing additives showed a great potential use of enzymes in biotechnology and medical engineering fields.

• Journal of Nutrition and Health
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• 제4권1호
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• pp.21-28
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• 1971

1. The effects of chloroform to the tissue lactic dehydrogenase (LDH) activities and its isozymes and to the tissue glutamic dehydrogenase (GDH) activities and its isoaymes are studied using the experimental albino male adult rats in this paper. The tissues studies are liver, kidney, heart, and brain. Besides the control group, two experimental groups are studied providing succeedingly 4 days interpariental administrations of chloroform, 0.0025ml and 0.025ml per day respectively. The changes of body weights, weights of organs, activities of GDH and LDH and their isozymes of each tissues, are analysed. 2. The body weights of rats are decreased due to the chloroform administration. 3. There are no significant differences of weights of organs due to the chloroform administration. 4. The significant decreases of tissue GDH activities and the significant changes in percent distribution of the GDH isozymes are found due to the chloroform administration. This weight be interpretated that chloroform effects to the protein and amino acid metabolism of rats. 5. Due to the chloroform administration, the significant changes in tissue LDH activities and in percent distribution of tissue LDH isozymes indicating the decreases of $LDH_1$ which is the aerobic heart type and the increase of $LDH_5$ which is the anaerobic muscle type, are observed. This could be estimated that chloroform effects to the carbohydrate metabolism, particularly to the anaerobic glycolysis of rats.

• Natural Product Sciences
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• 제21권1호
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• pp.54-58
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• 2015

The protective effect of EtOAc fraction of Limonium tetragonum extract (EALT) against alcohol-induced hepatotoxicity was assessed following acute ethanol intoxication in Spraque-Dawley rats. EALT (200 mg/kg p.o.) was administrated once before alcohol intake (8 g/kg, p.o.). Blood ethanol concentration, and the activities of alcohol metabolic enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in the liver were measured. Also, the formation of malondialdehyde (MDA) and the activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GSH-px), catalase were determined after acute alcohol exposure. Pretreatment of rats received ethanol with EALT significantly decreased blood ethanol concentration and elevated the activities of ADH and ALDH in liver. The increased MDA level was decreased, and the reduced activities of SOD, GSH-px and catalase were markedly preserved by the treatment with EALT. This study suggests that EALT prevent hepatic injury induced by acute alcohol which is likely related to its modulation on the alcohol metabolism and antioxidant enzymes activities.

• Journal of Applied Biological Chemistry
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• 제42권1호
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• pp.1-6
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• 1999

Poly-${\beta}$-hydroxybutyrate (PHB) and enzymes related PHB metabolism have been measured in nitrogen-fixing symbiosis of chickpea and cowpea plants. Bacteroids from chickpea and cowpea contained PHB to 0.8% and 43% of their dry weight, respectively, whereas the free-living cells CC 1192 and I 16 produced $285{\pm}55mg$ and $157{\pm}18mg$ of PHB g (dry weight)$^{-1}$. To further understand why chickpea bacteroids contained little PHB, the enzyme activities of PHB metabolism (3-ketothiolase, acetoacetyl-CoA reductase, PHB depolymerase, and 3-hydroxybutyrate dehydrogenase), the TCA cycle (malate dehydrogenase, citrate synthase, and isocitrate dehydrogenase), and related reactions (malic enzyme, pyruvate dehydrogenase, and glutamate:2-oxoglutarate transaminase) were compared in extracts from chickpea and cowpea bacteroids and the respective free-living bacteria. Significant differences were observed between chickpea and cowpea bacteroids and between the bacteroid and free-living forms of CC 1192, with respect to the capacity for some of these reactions. It is indicated that a greater potential for oxidizing malate to oxaloacetate in chickpea bacteroids could be a factor that favors the utilization of acetyl-CoA in TCA cycle rather than for PHB synthesis.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.37-46
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• 2004

Stenotrophomonas maltophilia LK-24가 페놀화합물을 분해하는데 관련된 효소들과 페놀의 분해 산물을 분석한 결과 phenol hydrolase, catechol-2.3-dioxygenase, 2-hydroxymuconic semialdehyde dehydrogenase, 2-hydroxymuconic semialdehyde hydroxylase, 및 acetaldehyde dehydrogenase를 확인하였다. 이러한 효소들의 활성으로 보아 페놀은 meta-pathway ring cleavage를 거치면서 분해되는 것으로 사료된다. 이러한 결과는 페놀화합물의 metabolic pathways를 이해하는데 많은 도움이 되며, phenolic-contaminated waste streams에 S. maltophilia LK-24를 사용할 수 있으리라 여겨진다.

• 한국미생물·생명공학회지
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• 제26권5호
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• pp.387-392
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• 1998

B. lactofermentum의 lysine 생합성에 있어서 DDH경로 및 ddh gene이 지닌 중요성을 조사하기 위하여, site-specific mutagenesis technique를 통하여 B. lactofermentum의 ddh gene을 disruption함으로서 DDH 경로를 차단시켰다. B. lactofermentum ddh mutant는 wild type 및 AEC내성 균주보다 성장이 매우 저조하였으며 lysine 생산량에서도 급격한 저하를 가져왔다. 이와 같이 B. lactofermentum이 DAP 경로만을 가졌을 때 세포의 성장 및 lysine 생산량에 있어서 극적인 저하를 가져왔기 때문에 B. lactofermentum에서의 DDH 경로는 meso-DAP 및 lysine 생합성에 있어 필수적인 경로로 작용한다는 것을 확인하였다. 그러므로 C. glutamicum과 B. lactofermentum과 같은 corynebacteria가 lysine을 많이 생산하는 것은 DDH 경로가 부가적으로 존재하기 때문이며, 이러한 DDH 경로는 metabolic flux가 증가되면 중간 대사물을 lysine으로 변화시키는 중요한 경로로 작용할 것이라 사료된다.

• Fisheries and Aquatic Sciences
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• 제14권2호
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• pp.79-88
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• 2011

The sea tangle, Laminaria japonica has long been used in Korea as a folk remedy to promote health. Gamma-amino butyric acid-enriched (5.56% of dry weight) sea tangle was obtained by fermentation with Lactobacillus brevis BJ-20 (FLJ). A suppressive effect of FLJ on carbon tetrachloride-induced hepatotoxicity has been shown previously. Alcohol administration to Sprague-Dawley rats leads to hepatotoxicity, as demonstrated by heightened levels of hepatic marker enzymes as well as increases in both the number and volume of lipid droplets as fatty liver progresses. However, FLJ attenuated alcohol-induced hepatotoxicity and the accumulation of lipid droplets following ethanol administration. Additionally, FLJ increased the activities and transcript levels of major alcoholmetabolizing enzymes, such as alcohol dehydrogenase and aldehyde dehydrogenase, and reduced blood concentrations of alcohol and acetaldehyde. These data suggest that FLJ protects against alcohol-induced hepatotoxicity and that FLJ could be used as an ingredient in functional foods to ameliorate the effects of excessive alcohol consumption.