• Genomics & Informatics
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• 제9권2호
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• pp.64-68
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• 2011

Monomelic amyotrophy (MA), also known as Hirayama disease, occurs mainly in young men and manifests as weakness and wasting of the muscles of the distal upper limbs. Here, we sought to identify a genetic basis for MA. Given the predominance of MA in males, we focused on candidate neurological disease genes located on the X chromosome, selecting two X-linked candidate genes, androgen receptor (AR ) and ubiquitin-like modifier activating enzyme 1 (UBA1). Screening for genetic variants using patients' genomic DNA revealed three known genetic variants in the coding region of the AR gene: one nonsynonymous single-nucleotide polymorphism (SNP; rs78686797) encoding Leu57Gln, and two variants of polymorphic trinucleotide repeat segments that encode polyglutamine (CAG repeat; rs5902610) and polyglycine (GGC repeat; rs3138869) tracts. Notably, the Leu57Gln polymorphism was found in two patients with MA from 24 MA patients, whereas no variants were found in 142 healthy male controls. However, the numbers of CAG and GGC repeats in the AR gene were within the normal range. These data suggest that the Leu57Gln polymorphism encoded by the X-linked AR gene may contribute to the development of MA.

• BMB Reports
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• 제35권2호
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• pp.228-235
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• 2002

Methionine aminopeptidase (MetAP) catalyzes the removal of an amino-terminal methionine from a newly synthesized polypeptide. The enzyme was purified to homogeneity from Bacillus stearothermophilus (KCTC 1752) by a procedure that involves heat precipitation and four sequential chromatographs (including DEAE-Sepharose ion exchange, hydroxylapatite, Ultrogel AcA 54 gel filtration, and Reactive red 120 dye affinity chromatography). The apparent molecular masses of the enzyme were 81,300 Da and 41,000 Da, as determined by gel filtration chromatography and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), respectively. This indicates that the enzyme is comprised of two identical subunits. The MetAP specifically hydrolyzed the N-terminal residue of Met-Ala-Ser that was used as a substrate, and exhibited a strong preference for Met-Ala-Ser over Leu-Gly-Gly, Leu-Ser-Phe, and Leu-Leu-Tyr. The enzyme has an optimal pH at 8.0, an optimal temperature at $80^{\circ}C$, and pI at 4.1. The enzyme was heat-stable, as its activity remained unaltered when incubated at $80^{\circ}C$ for 45 min. The Km and Vmax values of the enzyme were 3.0mM and 1.7 mmol/min/mg, respectively. The B. stearothernmophilus MetAP was completely inactivated by EDTA and required $Co^{2+}$ ion(s) for activation, suggesting the metal dependence of this enzyme.

• 한국환경보건학회지
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• 제31권2호
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• pp.127-133
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• 2005

This study was performed to investigate the competitive effect of Leuconostoc mesenteroides and Lactobacillus plantarum on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus. Leu. mesenteroides and Lac. plantarum were grown with A. parasiticus in a modified APT broth at $28^{\circ}C$ for 9 days. It was observed that the growth of A. parasiticus got lower when the two bacteria were inoculated simultaneously than when the mold grew alone. The pH of mixed culture of Leu. mesenteroides and Lac. plantarum showed significantly lower value than the pH of the pure culture of A. parasiticus (p<0.05). The acidity of the mixed culture group significantly increased compared with the control group (A. parasiticus alone group) (p<0.05). The aflatoxin $B_1$ production was significantly decreased in the mixed culture group than in the A. parasiticus alone group (p<0.05). Leu. mesenteroides showed the more efficient effect than Lac. plantarum. These results indicate that the two lactic acid bacteria have inhibitory effect on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus.

• 한국식품영양학회지
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• 제7권4호
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• pp.392-398
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• 1994

The purpose of this study was to predict the actions and roles of 10 strains of representative psychrotrophic lactic acid bacteria, in kimchi fermentation, which were Isolated from kimchi and identified as Leu. mesenteroides subsp. mesenteroides, Leu. mesenteroides subsp. dextranicum, Leu. lactic, Leu. paramesenteroides, Lac. bavaricus and Lac. homahiochii. For this, 0.01% of tactic starters were inoculated in germ free Korean cabbage-juice containing 2.5% NaCl, and then cultivated for 14 days at 1$0^{\circ}C$. All strains grew actively, and reached their stationary phase in 4 days. In death phase, the slopes of curves were much different each other by strains. The acidity increased rapidly between 2 and 4 days, and the pH decreased rapidly between 2 and 3 days. The total acidity was 0.5B~0.75%, the volatile acidity 0.04~0.18% and the pH 3.55~3.85, in final cultures. The cultures of Leuconostocs were better than those of lactobacilli on flavor test. It was thought that the ripening periods of kimchi would be much reduced, and that the over ripening would be also somewhat avoided, when these strains were used as starter bacteria for kimchi and the kimchi was fermented at low temperature.

• 약학회지
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• 제38권5호
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• pp.488-495
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• 1994

To evaluate the feasibility of transmucosal delivery of leucine enkephalin (Leu-Enk) and its synthetic analog, $[D-Ala^2]$-leucine enkephalinamide (YAGFL), their physicochemical stabilities in aqueous buffered solutions were first investigated using a stability indicating high performance liquid chromatography. The degradation of Leu-Enk and YAGFL followed the pseudo-first-order kinetics. From the pH-rate profiles, it was found that the maximal stability of the two pentapeptides was at the pH of about 5.0. The shelf lives $(t_{90%})$ for the degradation of Leu-Enk and YAGFL at pH 5.0 and $40^{\circ}C$ were found to be 48.13 and 50.9 days, respectively. From the temperature dependence of the degradation, activation energies for Leu-Enk and YAGFL were calculated to be 13.61 and 13.47 kcal/mole, respectively. A higher ionic strength and a higher initial peptide concentration in buffered solution slowed the degradation of the two pentapeptides. The addition of 2-hydroxypropyl-${\beta}$-cyclodextrin into the peptide solution did not affect the stability significantly.

• BMB Reports
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• 제34권2호
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• pp.109-113
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• 2001

The Serratia marcescens metalloprotease inhibitor (SmaPI) is a proteinase inhibitor toward Serratia marcescens metalloprotease (SMP). The three-dimensional structure of SmaPI was calculated by computer modeling using the structure complex between SMP and the Erwinia chrysanthemi inhibitor as a template. Based on this model structure, the substitution of the amino acid residues, Ala4, Leu-5, Pro-6, and Thr-7, were located at the hinge region of the N-terminal segment by site-directed mutagenesis. Although the A4R and T7A mutant SmaPIs showed a nearly full inhibitory activity, the inhibitory activity of SmaPI decreased significantly when the Leu-5 was converted to Ala, Gly, Ile, or Val. Surprisingly, the L5I and L5V mutant SmaPIs showed less inhibitory activities than the L5A mutant. From these results, we suggested that the orientations and positions of respective aliphatic groups in the side-chain of position 5 mainly affected the inhibitory activity of SmaPI. The overall side-chain hydrophobicity was only slightly affected. The side-chain of the Leu-5 residue contributed approximately 0.79 kcal/mol out of 8.44 kcal/mol to the binding of SmaPI with SMP The inhibitory activities of P6A and F6G were also severely decreased. The Pro-6 may have a critical role in maintaining the strict conformation of the N-terminal portion that may be important in the inhibitory activity of SmaPI. In conclusion, Leu-5 and Pro-6 have crucial roles in the inhibitory function of SmaPI toward SMP.

• 한국균학회지
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• 제20권3호
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• pp.222-228
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• 1992

사철 느타리버섯 영양요구성(營養要求性) 균주(菌株)를 팽이버섯 leu 2 유전자를 지닌 pM 301 백터를 이용(利用)하여 영양요구성(營養要求性)을 보완(補完) 시킴으로써 형질전환(形質轉換) 하였다. 형질전환균주(形質轉換菌株)의 균사생장(菌絲生長)을 버섯 완전배지(完全培地)나 버섯 최소(最小) 배지(培地)에서 비교(比較)하였다. 형질전환주(形質轉換株)는 1 핵(核) 균사(菌絲)와 교배(交配)후 자실체(子實體) 형태(形態)를 비교(比較)하고 포자 분석(分析)에 의하여 유전분석(分析)을 하였다. 자실체(子實體) 발생(發生)과 자실체(子實體) 모양이 형질전환주(形質轉換株)는 모균주와 다른 특성(特性)이 나타났다. 모균주(母菌株)는 교배형(交配型)이 $A_1B_1$으로 $A_2B_1$ 교배형(交配型)인 1핵(核) 균주(菌株)와 교배(交配)에 의하여 자실체(子實體)를 형성(形成)하지 못하나 형질전환주(形質轉換株)는 교배형(交配型)이 $A_1B_1$이고 $A_2B_1$ 1핵(核) 균주(菌株)와 교배(交配) 하였을때 자실체(子實體)를 형성(形成)하였다.

• 한국식품조리과학회지
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• 제7권2호
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• pp.89-95
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• 1991

김치발효 중에 주로 나타나는 Lac. plantarum, Leu. mesenteoides, Ped. acidilactici, Lac. brevis 등의 젖산균들이 김치발효에 미치는 영향을 규명하고자, 이 젖산균들을 순수 배양하여 염도 2.31%의 김치즙에 접종한 후 $30^{\circ}C$, $21^{\circ}C$, $7^{\circ}C$에서 발효시키면서 알코올 당의 변화 및 생균수의 변화를 관찰하고 관능검사를 하였다. Ethyl alcohol은 control group과 Leu. mesenteoides를 접종한 시료, 4종의 젖산균을 혼합 접종한 시료에서 검출되었으며 특히 $14^{\circ}C$에서 더 많은 양이 검출되었다. 당은 발효가 진행됨에 따라 감소하였고, 감소 정도는 pH 및 총산도의 변화와 잘 일치하였다. 총 생균수는 발효초기에는 증가하다가 서서히 감소하는 경향을 보였으며 control group과 Leu. mesenteroides에 있어서 김치가 적당히 익은 정도의 pH및 산도를 보이는 시기와 최고의 균수에 도달하는 시기가 일치하였다. 관능검사 결과 모든 온도에서 Control group이 냄새와 맛이 가장 좋았고 그 다음 4종의 젖산균을 혼합접종한 시료 Leu. mesentenoides를 접종한 시료의 순으로 나타났으며, 온도에 있어서는 $14^{\circ}C$에서 맛과 냄새가 좋았다.

• 한국미생물·생명공학회지
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• 제16권4호
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• pp.287-292
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• 1988

두유를 L. acidophilus와 K. fragilis로 혼합발효시 균의 생육과 젖산발효에 미치는 아미노산의 영향을 알아보기 위하여 이 두균주가 어떠한 상호작용으로 두유 중의 유리아미노산들과 대두단백질을 이용하는지에 대하여 조사하였다. 두유를 L. acidophilus와 K. fragilis로 혼합발효시 K. fragilis는 두유중의 유리아미노산들을 이용하여 생육하나 부족한 것은 L. acidophilus에 의해 대두단백질이 가수분해되어 생성되는 여러 종류의 유리아미노산들 중 젖산균이 생육인자로 이용하지 않아 발효액에 축적되는 Leu., Phe., Lys., Arg., Glu., Asp., Ala. 등의 유리 아미노산들 특히 Leu., Phe., Lys.을 이용함으로써 K. fragilis의 생육이 촉진된다고 생각되었다. 이와 같은 두균의 아미노산 대사의 상호작용과 당대사의 상호작용(2)을 함께 고려할 경우 두유를 L. acidophilus와 K. fragilis로 혼합발효할 때 두균사이에는 공생관계 (symbiotic relationship)가 성립되었으며 이로 인하여 두유를 두균으로 혼합발효하는 것이 L. acidophilus만으로 단독발효하는 것보다 젖산생성량이 많고 젖산생성속도가 바르다는 것을 알 수 있었다.

• 한국식품영양과학회지
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• 제41권3호
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• pp.396-401
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• 2012

열무김치로부터 김치유산균을 분리하고 프로바이오틱스로 이용 가능한 균주를 선발하기 위하여 인체의 장관과 유사한 인체장모델시스템(SHIMS)을 이용한 in silico 실험을 수행하였다. 열무김치에서 분리한 5종과 표준균주 12종에 대해 내산성 및 내담즙산성을 시험하여 생존율이 높은 2종의 균주를 선발하였다. 선발한 균주를 SHIMS에서 시험하여 가장 높은 생존율을 나타낸 균주의 16S rRNA를 분석한 결과 Leu. mesenteroides로 동정되었으며 이 김치유산균을 Leu. mesenteroides K01으로 명명하였다. 이 균주는 SHIMS에서 생존율이 높았기 때문에 프로바이오틱스로 다양하게 이용할 가치가 있다고 판단된다.