• 생명과학회지
• /
• 제14권5호
• /
• pp.868-873
• /
• 2004

유용성이 확보된 L-threonine의 효율적인 발효생산을 위하여 생산균주 E. coli MT201를 유전자재조합을 통하여 개량하고 적절한 탄소원을 발굴하여 전체적인 생산량 증대를 도모하였다. 먼저, 5 liter발효조에서 유가식 배양을 통하여 생산균주 E. coli MT201이 균체량이 52($OD_{660}$)일때 57 g/1의 생산량을 보이는 것을 확인하였다. L-Threonine의 생산성 향상을 위하여 균체 내에서 생합성 전구물질인 oxaloacetate를 충분하게 공급하기 위해 C. glutamicum 유래의 pyruvate carboxylase의 유전자를 plasmid pPYC의 형태로 E. coli MT201에 도입하였다(E. coli MT/PYC). 그렇지만 E. coli MT/PYC을 배양한 결과로부터 E. coli MT201와 비교할 때 균체증식 및 생산량이 모두 감소하는 경향을 보였으며, 이를 해결하기 위하여 플라스크배양을 통하여 포도당과 sodium citrate를 1.5:3.5의 비율로 배지 중에 첨가하였을 때 이들 문제가 개선되는 것을 관찰하였다. 상기 비율의 탄소원 조건하에서 5liter 발효조를 이용한 유가식 배양에서 배양 75시간째에 L-threonine의 생산량 및 균체량($OD_{660}$)이 각각 75.7 g/l와 48로 효율적으로 향상되는 것을 알 수 있었다. 이는 과도한 anaplerosis에 의한 TCA 회로의 불균형을 중간산물인 citric acid를 sodium citrate의 형태로 공급함으로써 E. coli MT/PYC에서 균체증식이 정상화됨을 의미한다.

• 한국패류학회지
• /
• 제11권1호
• /
• pp.51-61
• /
• 1995

A horizontal starch gal electrophoresis for enzyme proteins extracted from 3 species of Korean planorbid snails; Gyraulus convexiusculus, Hippeutis cantori and Segmentina hemisphaerula was carried out in order to elucidate their genetic relationships.The results from 12 enzymes employed in three different kinds of buffer systems are summarized as follows:1) Two loci from each enzyme of aldehyde oxidase, esterase, glucose phosphate isomerase. isocitrate dehydrogenase, leucine aminopeptidase, malate dehyogenase, peptidase and xanthine oxidase were detected, and only one locus was observed from each of the following four enzymes: 6-phosphogluconate dehydrogenase, glyceraldehyde-phosphate dehydrogenase, glutamate oxaloacetate transaminase and glycerol-3-phosphate dehydrogenase.2) Most of loci in 3 species of planorbid snails employed showed homozygous and monomorphic banding patterns and some of them were specifis as genetic markers among different species. However, a few of loci (EST-1. EST-2 and GPI-2)showed polymorphic banding patterns. 3)Hippeutis cantori and Segmentina hemisphaerula were more closely clustered in a dendrogram with the genetic iddentity value of 0.431, and these two species were lineated with Gyraulus convexiusculus as another cluster at the value of 0.294.In summarizing the above results, three species of Korean planorbid snails employed in this study mostly showed monomorphic enzyme protein banding patterns and genetic differences specific among 3 species.

• 동아시아식생활학회지
• /
• 제16권2호
• /
• pp.165-173
• /
• 2006

To investigate the effects of yellow soybean powder on serum lipid level and enzyme activities, male Sprague-Dawley(SD) rats were given hyperlipidemic diets for 6 weeks. Rats(n=8) were divided into three groups consisting the normal group(N), hyperlipidemic diets group(C) and hyperlipidemic diets and yellow soybean powder group(YSP). YSP group lowered triglyceride, total lipid, phospholpid, ester-cholesterol and free-cholesterl than control group. YSP group lowered total-cholesterol, VLDL-cholesterol and LDL-cholesterol but increased HDL-cholesterol of the serum compared to the control group. Athergenic Index(AI) and LHR(LDL-cholesterol/HDL-cholesterol ratio) of YSP group was decreased by control group (p<0.05). On the other hand, glutamic oxaloacetate transaminase(GOT), glutamic pyruvate transaminase (GTP), lactate dehydrogenase(LDHase) and alkaline phosphatase(ALP) enzymes activities were decreased by hyperlipidemic diets group (C). These results suggest that yellow soybean powder fed a lipid lowering effect in serum of rats.

• Advances in Traditional Medicine
• /
• 제10권1호
• /
• pp.29-36
• /
• 2010

The present study was aimed to investigate the hepatoprotective and antioxidant activities of ethanol extract from Monochoria vaginalis (250 mg/kg and 500 mg/kg B/W) on acetaminophen (APAP) induced rat hepatic injury. Monochoria vaginalis is a traditional medicinal plant that is commonly used to treat and improve liver conditions in India and other Asian countries. The development of hepatotoxicity induced by APAP is promoted by oxidative stress. APAP treated group significantly (P < 0.01) elevated the serum enzymatic levels like glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, alkaline phosphatase (SALP), total bilirubin and malondialdehyde (MDA), which were restored towards normalization significantly (P < 0.01) thanol extract of yonochoria vagin is (EEMV). In addition, the EEMV significantly (P < 0.01) elevated the decreased level of total protein and antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-s-transferase and reduced glutathione. Apart from these, histopathological changes also showed the protective nature of the EEMV against APAP induced hepatic damage in liver tissues. The activity of EEMV at 500 mg/kg B/W was comparable to the standard drug silymarin (25 mg/kg B/W). In conclusion, these data suggest that the EEMV possess hepatoprotective and antioxidant effects against APAP-induced hepatotoxicity and oxidative stress in rats.

• 대한의생명과학회지
• /
• 제12권1호
• /
• pp.43-48
• /
• 2006

Present study aimed to investigate recovering effect of propolis on blood components and tissues of mouse after low dose irradiation. It is verified that the contents of Fe, Mg, P, Zn and Cu in propolis dosed blood are increased slightly than irradiated blood, however, the contents of Ba and Pb are decreased to one tenth than irradiated blood and the contents of Fe and P are increased to 10% than control group. We consider this result as the propolis acts a role of defence factor minimizing changes of elements caused by irradiation in blood. Among the blood components, Glutamate oxaloacetate transaminase (GOT) value is increased after the radiation but after dosed with propolis and irradiated the value is decreased, suggesting that propolis as a buffering material against irradiation. After dosed with propolis, a number of spermatogenic cells are lowered in testis tissue, however, nucleus and cytoplasm are clearly observed in spermatogonia, spermatocytes and spermatid cells. And nucleus and membrane of cells in the proximal convoluted tubule of renal tissue are clearly observed. Also, cytoplasmand membrane of surface mucous cells in stomach tissue are appeared in normal which is almost like those of control group. We consider that the propolis used in this study is preventing deformations of cells increasing resistance capacity against irradiation rather than recovering damaged tissues.

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

• 셀메드
• /
• 제4권3호
• /
• pp.18.1-18.5
• /
• 2014

Leea asiatica (L.) Ridsdale, a folk medicinal plant is used by the ethnic people of North East India for the treatment of hepatic disorder. In this study, we have investigated the hepatoprotective and antioxidant activity of L. asiatica leaves against acetaminophen induced hepatotoxicity. Methanol extract of L. asiatica (150 and 300 mg/kg/day, p.o.) were administered to rats for three consecutive days followed by single acetaminophen (3000 mg/kg, p.o.) administration on $3^{rd}$ day. After 48 h of acetaminophen administration animals were sacrificed and biochemical estimation of serum, in vivo antioxidant activity using liver tissue were carried out. High levels of serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, serum alkaline phosphatase, total bilirubin, direct bilirubin, total cholesterol and triglycerides were observed in disease control group, which found near to normal in extract treated groups. Higher dose exhibited significant hepatoprotective activity against acetaminophen induced toxicity. Level of superoxide dismutase, catalase, glutathione peroxidase in liver tissue, and reduced glutathione in liver and blood were also significantly increased in extract (300 mg/kg) treated animals compare to disease control group. In this study we found that leaves of L. asiatica exhibited potent hepatoprotective activity against acetaminophen induced hepatic damage in experimental animals which justify the folklore claim, and the possible mechanism of this activity may be due to strong antioxidant activities of extract.

• Nutrition Research and Practice
• /
• 제14권4호
• /
• pp.309-321
• /
• 2020

BACKGROUND/OBJECTIVES: The present study aimed to evaluate the effects of folic acid supplementation in high-fructose-induced hepatic steatosis and clarify the underlying mechanism of folic acid supplementation. MATERIALS/METHODS: Male SD rats were fed control, 64% high-fructose diet, or 64% high-fructose diet with folic acid for eight weeks. Plasma glutamate-pyruvate transaminase, glutamate-oxaloacetate transaminase, lipid profiles, hepatic lipid content, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) were measured. RESULTS: The HF diet significantly increased hepatic total lipid and triglyceride (TG) and decreased hepatic SAM, SAH, and SAM:SAH ratio. In rats fed a high fructose diet, folic acid supplementation significantly reduced hepatic TG, increased hepatic SAM, and alleviated hepatic steatosis. Moreover, folic acid supplementation in rats fed high fructose enhanced the levels of phosphorylated AMP-activated protein kinase (AMPK) and liver kinase B (LKB1) and inhibited phosphorylation of acetyl coenzyme A carboxylase (ACC) in the liver. CONCLUSIONS: These results suggest that the protective effect of folic acid supplementation in rats fed high fructose may include the activation of LKB1/AMPK/ACC and increased SAM in the liver, which inhibit hepatic lipogenesis, thus ameliorating hepatic steatosis. The present study may provide evidence for the beneficial effects of folic acid supplementation in the treatment of non-alcoholic fatty liver disease.

• 미생물학회지
• /
• 제31권3호
• /
• pp.237-244
• /
• 1993

Aspartate aminotransferase (ASAT) (L-aspartate : 2-oxyoglutarate, EC 2.6. 1. 1.) from Streptomyces fradiae NRRL 2702 has been purified by acetone precipitation, DEAE-cellulose, hydroxyapatite, and preparative electrophoresis (Prep cell), of which the last was the most effective step in the purification of ASAT. The molecular mass was estimated to be 54,000 dalton by SDS-PAGE and 120,000 dalton by gel filtration chromatography. Preparative isoelectric focusing of purified ASAT resulted in one polypeptide band with a pI of 4.2, showing homogeneity and indicating that the enzyme is composed of two identical subunits. The enzyme was specific for L-aspartate as an amino donor ; the $K_{m}$ values were determined to be 2.7 mM for L-aspartate, 0.7 mM for 2-oxoglutarate, 12.8 mM for L-glutamate, and 0.15 mM for oxaloacetate. The enzyme was relatively heat-stable, having maximum activity at 55.deg.C, and it had a broad pH optimum ranging from 5.5 to 8.0. The activity of the purified enzyme was not inhibited by ammonium ions. This paper reports the first purification and characterization of the aspartate aminotransferase from a species of Streptomyces.s.

• Journal of Nutrition and Health
• /
• 제40권3호
• /
• pp.229-234
• /
• 2007

This study was conducted to investigate the effect of different kinds of traditional Korean soybeans on blood and liver lipids and lipid peroxidation. SD male rats (n=48) were assigned to six different groups and provided experimental diets for 28 days. The protein source of the diet was casein, isolated soy protein (ISP), or casein plus traditional soy powders (yellow bean, huktae, jinuni or seorietae). The ISP, jinuni and seorietae diet decreased blood triglyceride compared to casein group. The ISP groups had lower hepatic total lipid and triglycerides than casein groups. The yellow bean and seorietae group had hepatic lipid lowering effects, but the effect was not found in huktae and jinuni group. The glutamate-oxaloacetate transaminase activity was significantly decreased in ISP and jinuni groups than in casein group. The glutamate-pyruvate transaminase activity was also decreased in ISP group. The results of this study suggest that jinuni, yellow bean and seorietae groups are more effective in lowering body lipids than huktae group.