• 한국식품영양과학회지
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• 제23권1호
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• pp.7-12
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• 1994

철보충이 납종독된 흰쥐의 체내 무기질 함량과 DALAD activity 및 해독에 미치는 영향을 관찰하기 위해, 흰쥐에게 납 2,000ppm을 함유한 식수를 제한없이 주면서, 철분 100ppm, 500ppm을 보충한 식이로 5주동안 사육하여 얻을 결과는 다음과 같다. 체중증가량, 식이섭취량 및 식이효율은 납급여군이 대조군보다 낮게 나타났으며, 철보충납급여군은 납단독급여군보다 높은 것으로 나타났다. 간과 심장의 무게는 차이를 보이지 않았으나, 신장은 납급여군이 대조군보다 증가를 보였다. 비장은 납단독급여군에서만 증가를 보였고, 철보충납급여군에서는 대조군과 차이를 보이지 않았다. 헤마토크릿치는 철보충납급여군에서는 대조군과 차이를 보이지 않았으나, 납단독급여군은 유의적인 감소를 보였다. DALAD activity는 혈액과 간 모두 납급여군에서 대조군보다 유의적인 감소를 보였으나, 납단독급여군보다 철보충납급여군이 높게 나타났고, 철보충수준이 높을수록 높게 나타났다. 혈청과 간의 amino-transferase activity는 철보충납급여군에서는 대조군과 비슷한 경향을 보였으나 납단독급여군에서는 유의적인 증가를 보였다. 혈청 납함량은 납단독급여군과 철보충납급여군 사이에 차이를 보이지 않았으나, 간의 납함량은 철보충납급여군이 납단독급여군보다 높게 나타났다. 혈청 철함량은 납급여군이 대조군보다 감소했으나, 간의 철함량은 납급여군에서 높게 나타났으며, 철보충납급여군이 납단독급여군보다 증가를 보였다. 혈청과 간의 구리함량은 납단독급여군은 대조군과의 차이를 보이지 않았으나, 철보충납급여군은 감소를 보였다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
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• pp.205.2-205
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• 1996

No Abstract, See Full Text

• 한국결정학회:학술대회논문집
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• 한국결정학회 2001년도 임시총회 및 추계학술대회연구발표회(한국결정학회)
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• pp.6-7
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• 2001

• Bulletin of the Korean Chemical Society
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• 제14권6호
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• pp.652-654
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• 1993

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2001년도 추계학술대회
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• pp.146-156
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• 2001

The biosynthetic gene clusters for bluensomycin and spectinomycin were isolated and characterized from the bluensomycin producer, Streptomyces bluensis ATCC27420 and the spectinomycin producer, Streptomyces spectabilis ATCC27741, respectively. PCR primers were designed specifically to amplify a segment of dTDP-glucose synthase gene based on its conserved sequences of several actinomycete strains. By screening cosmid libraries using amplified PCR fragments, 30-kb and 45-kb DNA fragments were isolated from Streptomyces bluensis and Streptomyces spectabilis, respectively. Sequencing analysis of them revealed that each contains 15 open reading frames (ORFs). Some of these ORFs were turned out to be antibiotic resistance genes (blmA and speN), dTDP-glucose synthase genes (blmD and spcD), and dTDP-D-glucose 4,6-dehydratase genes (blmE and spcE), suggesting that the blm and spec gene clusters are likely involved in the biosynthesis of bluensomycin and spectinomycin, respectively.

• BMB Reports
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• 제28권2호
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• pp.124-128
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• 1995

Biodegradative threonine dehydratase purified from Serratia marcescens ATCC 25419 was inactivated by the arginine specific modification reagent, phenylglyoxal (PGO) and the lysine modification reagent, pyridoxal 5'-phosphate (PLP). The inactivation by PGO was protected by L-threonine and L-serine. The second order rate constant for the inactivation of the enzyme by PGO was calculated to be 136 $M^{-1}min^{-1}$. The reaction order with respect to PGO was 0.83. The inactivation of the enzyme by PGO was reversed upon addition of excess hydroxylamine. The inactivation of the enzyme by PLP was protected by L-threonine, L-serine, and a-aminobutyrate. The second order rate constant for the inactivation of the enzyme by PLP was 157 $M^{-1}min^{-1}$ and the order of reaction with respect to PLP was 1.0. The inactivation of the enzyme by PLP was reversed upon addition of excess acetic anhydride. Other chemical modification reagents such as N-ethylmaleimide, 5,5'-dithiobis (2-nitrobenzoate), iodoacetamide, sodium azide, phenylmethyl sulfonylfluoride and diethylpyrocarbonate had no effect on the enzyme activity. These results suggest that essential arginine and lysine residues may be located at or near the active site.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1310-1317
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• 2004

The extracellular production of 5-aminolevulinic acid (ALA) by recombinant E. coli BL21 harboring a fusion gene hemA was investigated in a fermenter. For this purpose, the effects of various physiological factors, such as isopropylthio­$\beta$-D-galactopyranoside (IPTG) concentrations and the time of induction, on enzyme activity were studied. Optimum concentrations of glycine and succinic acid were found to be 30 mM and 90 mM, respectively. When the cells were permitted to grow for 2 h prior to the addition of 0.1 mM IPTG, the activity of ALA synthase was higher than when IPTG was initially added. A 36-fold increase in the activity was observed with only 0.1 mM IPTG added. The pH of the medium also influenced the ALA synthase activity with the maximal activity occurring at pH 6.5. In recombinant E. coli extracts, the repeated addition of glycine and D-glucose increased the production of ALA and the inhibited intracellular ALA dehydratase activity, with up to 32 mM ALA being produced in the cultivation.

• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.668-673
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• 2013

A recombinant E. coli co-expressing ALA synthase (hemA), NADP-dependent malic enzyme (maeB), and dicarboxylic acid transporter (dctA) was reported to synthesize porphyrin derivatives including iron-containing heme. To enhance the synthesis of bacterial heme, five genes of the porphyrin biosynthetic pathway [pantothenate kinase (coaA), ALA dehydratase (hemB), 1-hydroxymethylbilane synthase (hemC), uroporphyrinogen III synthase (hemD), and uroporphyrinogen III decarboxylase (hemE)] were amplified in the recombinant E. coli co-expressing hemA-maeB-dctA. Pantothenate kinase expression enabled the recombinant E. coli to accumulate intracellular CoA. Intracellular ALA was the most enhanced by uroporphyrinogen III synthase expression, porphobilinogen was the most enhanced by ALA dehydratase expression, uroporphyrin and coproporphyrin were the most enhanced by 1-hydroxymethylbilane synthase expression. The strain co-expressing coaA, hemA, maeB, and dctA produced heme of $0.49{\mu}mol/g$-DCW, which was twice as much from the strain without coaA expression. Further pathway gene amplifications for the porphyrin derivatives are discussed based on the results.

• 한국식품영양과학회지
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• 제26권3호
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• pp.488-493
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• 1997

This study was designed to investigate the effects of Korean Pueraria radix extract in Pb administered rats. Pb exposed rats were given 1% Pb in the diet. $\delta$-Adminolevulinic acid(DALA) and urinary glucose levels were increased with Pb administration and were lower in the Pb group than in the group administered Pb alone. Hematocrit value was decreased with Pb administration and was higher in the Pb group than in the C-Pb grou. $\delta$-Aminolevulinic acid dehydratase (DALAD) activity was decreased in the Pb group. ALT and AST were increased by Pb added and were lower in the Pb group than in the C-Pb group. Serum Pb content was higher in the Pb exposed rats than in the control groups, and no significant difference was found due to extract of Pueraria radix supplementation. Levels of liver, kidney and femur lead were reduced by Pueraria radix. Lead contents in feces and urine were higher in the Pb added groups than in the control group, and level of feces lead was increased by extract of Pueraria radix.

• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.297-301
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• 2004

The dTDP-D-glucose 4,6-dehydratase from Salmonella enterica was immobilized using covalent binding to cyanogen bromide activated sepharose. The immobilized enzyme was used to produce dTDP-4-keto-6-deoxy-D-glucose, a key sugar intermediate that can be used economically to produce diverse classes of unusual sugars appended in various antibiotics. The enzyme was immobilized on the sepharose after activation with cyanogen bromide. The maximum immobilization (80.03％) was achieved after 14 h of coupling. The covalently immobilized enzyme was stable, and an average of 78.4 ％ conversion was achieved until 120 h of immobilization when it was repeatedly used. Similar conversion was noticed for the first batch using the enzyme entrapped-hydrogel but activity was gradually decreased in the following batches. The production of dTDP-4-keto-6-deoxy-D-glucose by using an immobilized enzyme has high potential for commercial application.