• Journal of Life Science
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• v.8 no.3
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• pp.285-293
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• 1998

We have cloned an internal fragment of the putative transoisase gene of MLE in the silkworm, Bombyx mori, using PCR method with degenerative oligonucleotide primers designed to represent regions of amino acids encoding transposase. The resulting PCR clone, designed as BmoMAR, cords a partial ORF(152 a.a.) of MLE in which interrupted by five stop codons, and the sequence of its deduced amino acids showed 37% homology with Mos1, an active mariner, from Drosophila mauritiana. Furthermore, the BmoMAR exhibits nucleotide and amino acid homology with 59% and 37% from Apis mellifera and D. mauritiana 7.9 clone, respectively. This result strongly that a MLE is present in the genome of B. mori.

• Monthly Duck's Village
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• s.86
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• pp.57-61
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• 2010

이번 연구는 아플라톡신 $B_1(AFB_2)$의 독성이 오리의 생산성, 체내 기관, 간 효소 활성도, 외관상 소화율, 영양소 소화율에 미치는 영향을 알아보기 위한 것이다. 1일령의 육용오리 90마리를 3개의 처리군으로 나눠 10마리씩 펜에서 사육하였다. 그룹1은 일반 사료를 급여하였고, 그룹 2와 3은 각각 아플라톡신 $20{\mu}g/kg$, $40{\mu}g/kg$이 포함된 오염된 쌀을 섞어 6주 동안 급여하였다. 그 결과 아플라톡신에 오염된 사료를 섭취한 그룹의 증체량과 사료 섭취량이 감소하였고, 사료요구률(feed to gain ratio), 간, 신장, 췌장의 무게가 높은 것으로 나타났다. 알라닌 아미노전이효소(ALT, serum alanine aminotransferase)와 혈중 아스파라진산 아미노전이효소(AST, aspartate aminotransferase)의 활성도도 아플라톡신 오염 그룹에서 유의성을 보이며 높았다. 아플라톡신 오염 그룹의 오리들의 십이지장에서 채취한 단백질 분해효소, 키모트립신, 트립신(이자액에서 분비되는 단백질 분해효소), 전분 가수 분해효소 등 소화효소의 활성도가 증가한 반면, 조단백질의 외관상 소화율은 유의성있게 낮은 것으로 나타났다. 이는 아플라톡신에 오염된 사료로가 오리의 생산성과 영양소의 외관상 소화율을 감소시키고 십이지장 내용물의 소화효소활성을 변화시킨다고 볼 수 있다.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.3
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• pp.241-248
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• 2021

The present study was conducted to assess the relationship between aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio and pulse pressure in Korean adults with hypertension. Data from 1,515 adults from the sixth Korean National Health and Nutrition Examination Survey (KNHANES VI-3, 2015) were analyzed. There were several key findings in the present study. First, aspartate aminotransferase (odds ratio [OR], 1.018; 95% confidence interval [CI], 1.002 to 1.033), alanine aminotransferase (OR, 0.982; 95% CI, 0.969 to 0.996), and aspartate aminotransferase/alanine aminotransferase ratio (OR, 1.367; 95% CI, 1.027 to 1.819) were the independent factors determining high pulse pressure. Second, after adjusting for related variables [age, gender, smoking, alcohol consumption, regular exercise, total cholesterol (TC), triglycerides (TGs), high-density lipoprotein-cholesterol (HDL-C), fasting plasma glucose (FPG), body mass index (BMI), and waist circumference (WC)], the ORs of high pulse pressure with the 1st quartile as a reference were significantly higher in the 4th quartile of aspartate aminotransferase/alanine aminotransferase ratio [1.632 (95% CI, 1.113~2.393)]. The high pulse pressure was positively associated with aspartate aminotransferase and alanine aminotransferase/alanine aminotransferase ratio in Korean adults with hypertension, but was inversely associated with alanine aminotransferase.

• The Microorganisms and Industry
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• v.27 no.1
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• pp.2-17
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• 2001

Cyclomaltodextrinase(CDase, EC 3.2.1.54), maltogenic amylase(EC 3.2.1.133). neopullulanase(EC 3.2.1.135)는 cyclomaltodextrin(CD), pullulan 및 전분을 가수분해하는 효소들이다. 이 효소들은 $\alpha$-1,4-Ο-glycosidic 결합에 작용하여 CD와 전분을 말토오스로 pullulan을 panose로 가수분해할 뿐만 아니라 올리고당들을 다양한 당 수용체 분자들의 C-3, C-4. C-6 수산기로 전이시키는 활성도 갖고 있다. 이러한 특성들은 기존의 $\alpha$-amylase를 비롯한 판수화물 분해효소들과 뚜렷이 구별되는 것으로 전분 분해효소들의 분류체계에 새로운 기준점을 제시한다고 하겠다. 본 총설에서는 CDase, maltogenic amylase, neopullulanase처럼 pullulan이나 전분보다 CD를 훨씬 더 잘 분해하는 효소들과 Thermoactinomyces vulgaris amylase II(TVA II)처럼 CD를 분해하기는 하나 pullulan을 더 잘 분해하는 효소들의 생화학적, 효소적, 구조적 특성들을 종합하여 소개하고자 하였다. 이 효소들은 40~60% 정도로 아미노산 서열이 동일하고, 세포 내에 존재하며, 분자량이 62~90 kDa로 $\alpha$-amylase보다 다소 크다. 아미노산 서열 비교분석 및 maltogenic amylase와 TVA II 등의 3차구조 분석 결과, 이 효소들은 아미노 말단에 보통 $\alpha$-amylase에는 존재하지 않는 약 130개 아미노산으로된 영역을 갖고 있어 이를 매개로 이합체를 형성할 수 있는 것으로 나타났다. 이합체-단위체 평형은 염 농도, 효소 농도, 산도 등에 의해 조절되고 단위체와 이합체 모두 효소환성을 갖고 있으나, 기질 특이성이 다르며 단위체는 전분을, 이합체는 CD를 선호하는데 이는 이합체 형성 시 활성부위의 구조적 변화에 따른 것으로 분석되었다. 본 총설에서는 CD 분해효소들의 다양한 기질 특이성을 올리고머 형성 등의 구조적 특성과 관련하여 논함으로써 관련 효소들의 분류체계를 보다 명확히 할 수 있는 자료를 제공하고자 하였으며, 이러한 효소들의 생리적 기능 및 산업적 이용에 대해 제안하고자 하였다.

• Food Industry And Nutrition
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• v.2 no.1
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• pp.7-9
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• 1997

내열설 미생물, Thermus caldophilus CK24에 대한 탄수화물 생합성을 연구하는 과정에서 다양한 탄수화물 관련효소를 탐색하고 그레 대한 생화학적 및 분자생물학적 연구를 수행하고 있다. 일차로 내열성 미생물내 1) 당핵산염 합성효소와 당전이 효소, 2) 탄수화물 대사효소. 3)탄수화물 분해 및 전환효소의 존재를 HPLC/Bio-LC분석을 통하여 확인하고 이들에 대한 연구를 진행하고 있다. 본 연구발표에서는 포도당을 과당으로 전환하는 이성화효소(xylose isomerase), 그리고 맥아당을 트레할로스로 전환하는 트레할로스 합성효소(trehalose synthase)를 소개하고저 한다. 이성화효소는 이미 산업적 과당 생산에서 대규모적으로 사용되고 있는 식품산업효소이다. 본 연구에서는 Thermus caldophilus GK24, Thermus thermophilus HB8, Thermus flavus AT62 3종의 내열성 미생물에 대한 이성화효소 유전자를 클로닝 하고, 각 재조합하고 이성화효소를 대량생산하였다. 이 내열성 이성화효소는 최적 반응 온도가 8$0^{\circ}C$이고, 포도당을 과당으로 전환하는 수유른 55%이었다. 이러한 과당전환률은 이미 산업적으로 사용되고 있는 이성화효소의 과당전환률(43%)보다 훨씬 높은 것으로 과당 생산공정의 단순화의 생산성 향상에 결정적인 요인이라 할 수 있다. 한편 본 이성화효소의 산업적 특성을 증대하기 위하여 구조-기능관계 연구를 착수하였다. 우선 내열성 이산화 효소의 입체 구조를 결정하였고, 구조조정에 따른 기능적 특성을 조사하기 위하여 특정 위치의 선택적 변이 연구를 진행하고 있다. 끝으로 포도당 전이 효소를 추적하던 과정에서 맥아당을 트레할로스로 전환하는 새로운 효소를 Thermus caldo-philus GK24에서 발견하였다. 그 트레할로스 합성효소는 분자량이 약 110kDa이고 최적 반응온도가 75$^{\circ}C$이면, 조효소없이 맥아당을 트레할로스로 80%이상 전환해 주는 가역효소이었다. 본 연구에서는 효소반응의 조건과 특성을 조사하였고, 효소 아미노-밀단의 서열결정정보를 통하여 효소의 유전자를 클로닝 하고 그 유전자의 구조와 발현연구를 진행하고 있다.

• Journal of Life Science
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• v.21 no.2
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• pp.221-226
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• 2011

The gene encoding 4-$\alpha$-glucanotransferase (mgtA) from Thermotoga neapolitana was cloned and expressed in Escherichia coli in order to investigate whether this enzyme was capable of producing cycloamylose for industrial applications. MgtA was purified to homogeneity by HiTrap Q HP and Sephacryl S-200 HR column chromatographies. The size of the enzyme as determined by SDS-PAGE was about 52 kDa, which was in good agreement with its deduced molecular mass of 51.9 kDa. The optimal temperature and pH for the activity of the 4-$\alpha$-glucanotransferase was found to be $85^{\circ}C$ and 6.5, respectively. The enzyme hydrolyzed the 1,4-$\alpha$-glucosidic bonds in oligomeric 1,4-$\alpha$-glucans and transferred oligosaccharides (maltotriose being the shortest one) to acceptor maltodextrins. However, the enzymes had no activity against pullulan, glycogen, and other di- or trioligosaccharides with rare types of $\alpha$-bond. MgtA is distinguished from 4-$\alpha$-glucanotransferase from Thermotoga maritima in that it can convert maltotriose into maltooligosaccharides. The treatment of glucoamylase after the reaction of MgtA with maltotriose, maltotetraose, maltopentaose, or maltohexaose as sole substrate revealed that MgtA yielded linear maltooligosaccharides instead of cycloamylose.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.1
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• pp.9-15
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• 2023

The purpose of this study was to analyze the relationship between diabetes and liver function test results. Unlike type 2 diabetes mellitus (T2DM), hepatogenous diabetes is caused by abnormal liver function. In this study, the relationship between liver enzymes, aspartate aminotransferase (AST), alanine transaminase (ALT), and the AST/ALT ratio (De Ritis ratio), indicating liver function, and diabetes-related tests was analyzed. The results of the study showed a positive correlation between AST and glucose (r=0.14, P<0.01), ALT and glucose (r=0.21, P<0.01), AST and glycated hemoglobin (HbA1c) (r=0.15, P<0.01), and ALT and HbA1c (r=0.20, P<0.01). The De Ritis ratio showed a negative correlation with glucose (r=-0.20, P<0.01) and HbA1c (r=-0.14, P<0.01). The results of regression analysis with AST, ALT, and the De Ritis ratio as independent variables and glucose (R²=0.05) and HbA1c (R²=0.04) as dependent variables revealed that the independent variables had a statistically significant effect on the dependent variables. AST showed a lower correlation between blood glucose and glycated hemoglobin than ALT, and an increase in ALT caused a decrease in the De Ritis ratio. Therefore, the De Ritis ratio can be said to be meaningful in relation to diabetes-related tests.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.867-872
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• 2002

This study was performed to investigate the optimum process conditions for manufacturing yeast extract from waste brewer's yeast using various enzymes. Contents of IMP, GMP, free amino acids, and crude protein of yeast extracts were measured by enzymes treatment. Crude protein contents of yeast extracts subjected to cell wall digestion enzyme treatment were 21.1, 33.6, and 28.0% for the control grouup, glucanase (0.5%, 12 h), and tunicase (1%, 18 h), respectively. Crude protein contents of yeast extracts subjected to protease treatment were 22.0, 30.8, and 29.8% for control group, bromelin (1%, 3 h), and protamex (1%, 3 h), respectively. Crude protein content of yeast extract subjected to glucanase and protamex mixed treatment was 34.4%. The total contents of IMP and GMP of yeast extracts subjected to G+P+A (glucanase+phosphodiesterase+adenyldeminase) and G+Pro+P+A (glucanase+protamex+phosphodiesterase+adenyldeaminase) treatments were 1,066 and 1,047 mg/100 g, respectively. The content of free amino acids of yeast extract was the highest (2,302 mg/100 g) in G+Pro+P+A treatment. Optimum concentration and process condition of enzyme treatment to obtain yeast extract with high IMP, GMP, and free amino acid content were in the order of glucanase (0.5%, 12 h), protamex (1%, 3h), phosphodiesterase (0.1%, 3 h) and adenyldeaminase (1%, 1.5 h) treatments.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.104-110
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• 2012

Glycosynthase is an active site nucleophile mutant enzyme, prepared from glycosidase, which is capable of synthesizing oligosaccharide derivatives without the hydrolysis of the product. Thermoacidophilic ${\alpha}$-glucosidase of Thermoplasma acidophilum (AglA) exhibits a transglycosylating activity yielding various glycosides. AglA was converted to glycosynthase by the substitution of the catalytic nucleophile Asp-408 residue into non-nucleophile glycine in order to increase its ability to synthesize various glycosides by transglycosylation. The glycosynthase mutant was purified by Ni-NTA chromatography and its glycoside-synthesizing activity was measured by using an external nucleophile, sodium formate buffer, providing maltose as a donor and p-nitrophenyl-${\alpha}$-D-glucopyranoside ($pNP{\alpha}G$) as an acceptor, respectively. In addition, $pNP{\alpha}G$ was examined for its feasibility to act as both a donor and an acceptor, and products were compared with those of the wildtype enzyme. The mutant enzyme was found to catalyze the formation of a specific product from $pNP{\alpha}G$ with a yield of 42.5% without further hydrolysis, while the wild-type enzyme produced two $pNP{\alpha}G$ products at low yields. The results demonstrate the possibility of satisfactory yields for the reactions in the presence of small amounts of acceptor, and demonstrate that the high activity of the mutant, at pHs below neutrality, was applicable in the transfer of glucose from the natural donor.

• Tuberculosis and Respiratory Diseases
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• v.66 no.6
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• pp.437-443
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• 2009

Background: The aim of this study was to consider the significance of pleural fluid adenosine deaminase (ADA) activity combined with lymphocyte/neutrophil (L/N) ratio in the diagnosis of tuberculous pleurisy (TBpl) in a region of intermediate prevalence of tuberculosis (TB). Methods: We collected data from 388 patients with exudative pleural effusions. The final diagnoses were compared to the results from our diagnostic method using pleural fluid ADA and L/N ratio. Results: 108 patients had a final diagnosis of TBpl; 102 cases had high levels of ADA ($\geq$40 IU/L). When we considered ADA $\geq$40 IU/L as a diagnostic criterion, the sensitivity was 94.4%, specificity 87.5%, and posttest posttest probability 74.5%. However, when we considered ADA $\geq$40 IU/L combined with the L/N ratio $\geq$0.75 as a diagnostic criterion, the specificity and post-test probability were rose to 97.5% and 93%, respectively. The other causes of high ADA and L/N ratios were lymphoma and metastatic carcinoma, but mass-like lesions were found on the chest radiographs or CT scans. Conclusion: To evaluate the causes of exudative pleural effusions in a region of intermediate prevalence of tuberculosis, we recommend measuring the pleural fluid ADA and L/N ratio first. If the result is high and malignancies are not suspected, it may be diagnostic of TBpl.