• Clinical and Experimental Pediatrics
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• 제48권10호
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• pp.1068-1075
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• 2005

목 적 : 성장호르몬 분비를 촉진하는 ghrelin는 여러 질병에서의 역할은 아직까지 잘 알려져 있지 않았다. 그러나 최근에 ghrelin 유전자 변이가 비만과 당뇨병과 관련이 있는 것으로 알려졌다. 현재까지 보고된 ghrelin 유전자 이상으로는 SNP인 Arg51Gln, Leu72Met, G274A가 있으며 이중 가장 흔한 이상인 Leu72Met 변이이다. 일반적으로 ghrelin 유전자의 Leu72Met와 같은 diallelic 다형성을 스크리닝하는데 SSCP, RFLP, sequencing 등이 사용되어 왔으나 향후 비만 환자들에서 가장 효과적이고 정확하게, 손쉽게 ghrelin 유전자의 Leu72Met 다형성 분석을 검출할 수 있는 스크리닝 방법을 찾아 임상적 적용에 이용하고자 하였다. 방 법 : 비만소아에서 ghrelin 유전자의 Leu72Met 다형성 분석을 PCR-RFLP, PCR-SSCP와 ARMS 분석 방법을 이용하여 비교분석하고 이들의 검사방법의 장단점을 알아보았다. 결 과 : PCR-RFLP, PCR-SSCP와 ARMS 분석 모두에서 allele 특이산물의 밴드가 뚜렷이 구별할 수 있었으며 상기 방법에 의한 결과는 모두에서 일치하였다. PCR-SSCP 방법은 점돌연변이의 존재 여부를 많은 시료를 대상으로 쉽게 분자학적 스크리닝할 수 있는 장점이 있으나 조작이 간단하지 않고 비용부담이 많다. BsrI 제한효소를 이용한 PCR-RFLP법은 비교적 용이하고 간단하여 널리 쓰이는 방법이지만 충분한 고농도의 DNA가 필요하며 전기영동 결과의 올바른 해석이 쉽지 않았다. 이에 비하여 ARMS 분석법은 위의 방법들보다는 간편하여 검사의 소요시간도 짧으며, 검출률이 높고 결과 해석이 매우 쉬웠다. 결 론 : 따라서 본 실험에서 시행한 ghrelin의 Leu72Met 유전자의 다형성을 결정하는 방법 중에는 ARMS 분석법이 정확하고 검사 분석법 및 결과 해석이 매우 쉽고 검사의 소요시간도 짧아 대량 검체에 적용에 매우 효과적으로 사료된다.

• 한국수산과학회지
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• 제20권6호
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• pp.582-590
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• 1987

말쥐치육 단백질의 가수분해물로 합성한 plastein을 식품단백질원으로서 고도이용 가능성을 구명하기 위하여 그의 기능성을 FPC 및 egg albumin과 비교 검토하였으며, 아울러 SEM에 의한 plastein 형상도 관찰하였다. 용해도는 plastein이 FPC 보다 용해도가 월등히 높았고, Glu-papain plastein은 pH변화에 관계없이 용해도가 $95\%$이상으로 높았으나 Leu-papain plastein의 용해도는 매우 낮았다. 가열시간이 길어짐에 따라 FPC는 용해도가 감소하는 경향을 보였으나 Glu-papain plastein은 가열시간에 관계없이 용해도가 $81\%$이상이었다. 분산성은 Glu-papain plastein과 protease plastein이 egg albumin의 그것과 비슷하였으나 ekfms plastein은 다소 분산성이 낮았다. 보수력은 FPC가 egg albumin보다 낮았으며, 지방흡수력은 Leu-papain plastein이 1.88ml/g으로 가장 높았고, 다른 plastein은 egg albumin의 그것과 비슷하였다. 유화성은 Leu-papain plastein이 $61.2\%$로 가장 높았으나 Glu-papain plastein은 $50.7\%$로 가장 낮았다. 유화안정성도 이와 같은 경향이었다. 포말성은 Leu-papain plastein과 Glu-papain plastein이 각각 $373\%,\;360\%$로 egg albumin의 $130\%$ 보다 우수하였다. 포말안정성은 모든 plastein이 50시간 이후에 소실되어 egg albumin의 36시간에 비해 높았다. 점도는 모든 plastein이 egg albumin에 비해 낮았다. SEM을 통해 본 plastein의 형상은 처리한 효소 종류에 따라 다소 차이를 보였으며, Glu-papain plastein과 Leu-papain plastein은 다른 plastein에 비해 특이한 부드러운 형상을 나타내었다.

• Journal of Pharmaceutical Investigation
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• 제38권4호
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• pp.255-259
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• 2008

The present study aimed to investigate the in-vitro characteristics of N4-amino acid derivatives of cytarabine for the oral delivery of cytarabine. After the synthesis of L-Ile-cytarabine, L-Leu-cytarabine and L-Arg-cytarabine, the gastrointestinal stability of each prodrug was examined using artificial gastric juice and intestinal fluids. The cellular uptake characteristics of prodrugs were also examined in Caco-2 cells. While L-Ile-cytarabine and L-Leu-cytarabine appeared to be stable in all the tested biological media during 4-hr incubation, L-Arg-cytarabine was rapidly disappeared within 5 min. Accordingly, the cellular uptake of L-Ile-cytarabine and L-Leu-cytarabine was significantly higher than that of its parent drug, cytarabine in Caco-2 cells but the cellular uptake of L-Arg-cytarabine was similar to that from its parent drug. The cellular uptake of L-Ile-cytarabine and L-Leu-cytarabine appeared to be saturable as drug concentration increased from 0.4 to 4 mM. Collectively, L-Ile-cytarabine and L-Leu-cytarabine could be promising candidates to improve the oral absorption of cytarabine via a saturable transport pathway.

• BMB Reports
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• 제34권3호
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• pp.244-249
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• 2001

The anabolic acetolactate synthase III was purified to homogeneity from Serratia marcescens using DEAE-Sepharose, Phenyl-Sepharose, and hydroxylapatite column chromatography The native molecular weight of the enzyme was approximately 165 kDa. The enzyme is composed of two large and two small subunits with molecular weights of 64 and 15 kDa, respectively. The N-terminal sequence of the large and small subunit of the enzyme was Ser-Ala-Thr-Pro-Gln-Pro-Ser-Thr-Arg-Phe-Thr-Cys-Ala-Gln-Leu-Ile-Ala-His-Leu and Met-Leu-Gln-Pro-Gln-Asp-Lys-Pro-Gln-Val-Ile-Leu-Glu-Leu-Ala-Val-Arg-Asn-His-Pro-Gly-Val-Met-Ser-His-Val, respectively. The optimum pH and pI value were 7.5 and 5.5, respectively The $IC_{50}$ values were $20\;{\mu}M$ and $14\;{\mu}M$ for valine and herbicide SU7, respectively. The substrate specificity ratio, R value, was determined to be approximately 40, which suggests that this enzyme prefers the formation of $\alpha$-aceto-$\alpha$-hydroxybutyrate leading to the synthesis of isoleucine.

• 한국미생물·생명공학회지
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• 제18권3호
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• pp.305-308
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• 1990

Shuttle plasmid vector인 pHN114를 이용하여 Kluyveromyces fragilis의 3-isopropylmalate dehydrogenase 유전자를 cloning 하였다. 그 결과 Saccharomyces cerevisiae의 leu2변이와 E.coli의 leuB변이를 상보하는 두가지 clone 체 pJK104와 pJK106을 얻었다. Restriction mapping 결과 이들은 서로 반대방향으로 삽입되어 있었으며 expression activity는 pJK104가 높았다. pJK104에 삽입된 유전자를 BglII와 SalI으로 끊은 1.6kb fragment를 probe 로 하여 Southern Hybridization 한 결과 유전자의 유래가 Kluyveromyces fragilis 임을 확인하였다.

• 한국미생물·생명공학회지
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• 제28권4호
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• pp.195-201
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• 2000

Glucoamylase of Saccharomyces diastaticus is produced as a large precursor composed of signal peptide (21 amino acid residues), Thr and Ser-rich region and functional glucoamylase. To evaluate the utility of the glucoamylase signal peptide (GSP) for the secretion of foreign proteins, four types of GSP mutants (ml : Pro-18 longrightarrowLeu-18, m2 : Tyr-13 longrightarrowLeu, m3 : Ser-9longrightarrowLeu-9, m4 : Asn-5 longrightarrowPro-5) were constructed and secretion efficiency of each mutant was compared with that of native GSP by the expression and secretion of Bacillus subtilis CMCase under the control of GAP in N-terminal domain and hydrophobic domain. n mutant 4, a polar amino acid was replaced by a helix - breaking Pro residue. CMCase activity assay and Western blot analysis revealed that CMCase secretion by GSP mutants replaced by Leu were increased compared with native GSP. In the case of m2 and m3, the substitution of Leu for Tyr-13 and Ser-9 in the hydrophobic region resulted in a twofold increase in the extracellular CMCase activity.

• 한국자원식물학회지
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• 제5권1호
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• pp.25-29
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• 1992

The proximate and amino acid composition of wild and cultivated Cynochum wilfordi, Codopsis lancolata and lxeris sonchifolia were analyzed. Cynochum wilfordi, had higher contents of sugar ascompared with Codonopsis lancolata and lxeris sonchifolia. Fats was 2-3 times higher in Cynochumwilordi then Codonopsis lancolata and lxeris sonchifolia. No significant difference in the contents wasfound between the open field root, spontanity and cultivated at 30'c in biotronroom at condonopsislanceolata. However, contents of protein was 12.8% in lxeris sonchifolia. Total amino acid were 1.5-1.8 times higher in lxeris sonchifolia. than Cynochum wilfordi and Codonopsis lancolata. The decresingorder of the amounts of amino acid infused from the Cynochum wilfordi samples was Glu, Arg, Asp,Leu, Pro, Lys, Codonopsis lancolata (Changdeuk) was Arg, Glu, Pro, Leu, Asp, Lys, Codonopsislanceilata(Chirisan) was Arg, Glu, Pro, Asp, Lys, Leu, Codonopsis lancolata(Yeanbeun) was Arg,Glu, Asp, Leu, Ser, Lys, and lxeris sonchifolia was Glu, Arg, Asp, Cys, Lys, Pro.

• Journal of Microbiology and Biotechnology
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• 제24권1호
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• pp.13-18
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• 2014

Bacillus subtilis JW-1 was isolated from rhizosphere soil as a potential biocontrol agent of bacterial wilt caused by Ralstonia solanacearum. Seed treatment followed by a soil drench application with this strain resulted in >80% reduction in bacterial wilt disease compared with that in the untreated control under greenhouse conditions. The antibacterial compound produced by strain JW-1 was purified by bioactivity-guided fractionation. Based on mass spectroscopy and nuclear magnetic resonance spectral data ($^1H$, $^{13}C$, $^1H-^1H$ correlation spectroscopies, rotating frame nuclear Overhauser effect spectroscopy, and heteronuclear multiple-bond correlation spectroscopy), the structure of this compound was elucidated as a cyclic lipopeptide composed of a heptapeptide (Gln-Leu-Leu-Val-Asp-Leu-Leu) bonded to a ${\beta}$-hydroxy-iso-hexadecanoic acid arranged in a lactone ring system.

• 한국식품영양학회지
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• 제12권1호
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• pp.69-76
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• 1999

In order to screen lactic acid bacterial starter having high antibacterial activity and giving good flavor in Dongchmi for Naengmyon antibacterial activity and acid producing ability of 24 strains of Kimchi lactic acid bacteria were tested. Among 24 strains tested Leuconostoc mesenteroides subsp. mesenteroides C16, Leu. paramesenteroides C18 Lactobacillus bavaricus B01, B06, C19, C32 Lac. homohiochii B21 and B22 showed high antibacterial activity and their antibacterial activities were more active against Listeria monocytogenes and Staphylococcus aureus than against Escherichia coli and Salmonella typhimurium. The odors of Dongchimi-juices fermented with Leu. mesenteroides or Leu. paramesenteroides were more favorable than those with Lac. bavaricus or Lac. homohiochii. But the odors of Naengmyon-broths which were made with each Dongchimi-juice were not significantly different each other. In consideration of antibacterial ac-tivity and flavor of Dongchimi-juice two strains of lactic acid bacteria Lac. homohiochii B21 and Leu. mes-enteroides subsp. mesenteroides C16 were finally screened out as Dongchimi starters.

• Advances in Energy Research
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• 제3권2호
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• pp.125-131
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• 2015

Prompt neutron lifetime calculations have been performed for the NIRR-1 reactor HEU and LEU cores using the 1/v insertion and the Adjoint flux weighing methods. Results of calculations obtained for the HEU and LEU cores are respectively $57.3{\pm}0.8$ and $47.5{\pm}0.7$ for the 1/v insertion and $56.9{\pm}0.3$ and $46.3{\pm}0.5$ for the Adjoint flux. There is a good agreement seen between the two methods for both cores. The prompt neutron lifetime was observed to be shorter in the LEU than for the HEU as expected. However, the Adjoint flux weighing method seemed to be the easiest method in calculating the prompt neutron lifetime for NIRR-1.