• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.57-63
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• 2003

Using fungal (Fusarium solani f. pisi) and bacterial (Pseudomonas mendocina) cutinases, the initial hydrolysis rate of p-nitrophenyl esters was systematically estimated for a wide range of enzyme and substrate concentrations using a 96-well microplate reader. Both cutinases exhibited a high substrate specificity; i.e. a high hydrolytic activity on p-nitrophenyl butyrate (PNB), yet extremely low activity on p-nitrophenyl palmitate (PNP). When compared to the hydrolysis of PNB and PNP by other hydrolases [lipases and esterases derived from different microbial sources, such as bacteria (Pseudomonas cepacia, Psedomonas furescens, Baciilus stearothermophilus), molds (Aspeillus niger, mucor miehei), and yeasts (Candida rugosa, Candida cylindracea)], the above substrate specificity would seem to be a unique characteristic of cutinases. Secondly, the hydrolytic activity of the cutinases on PNB appeared much faster than that of the other hydrolytic enzymes mentioned above. Furthermore, the current study proved that even when the cutinases were mixed with large amounts of other hydrolases (lipases or esterases), the Initial hydrolysis rate of PNB was determined only by the cutinase concentration for each PNB concentration. This property of cutinase activity would seem to result from a higher accessibility to the substrate PNB, compared with the other hydrolytic enzymes. Accordingly, these distinct properties of cutinases may be very useful in the rapid and easy isolation of various natural cutinases with different microbial sources, each of which may provide a novel industrial application with a specific enzymatic function.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.243-246
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• 2005

A novel esterase showing high enantioselectivity to (S)-ketoprofen ethyl ester was selected from fosmid environmental DNA library which is provided by Microbial Genomic & Applications Center. As a result of Blast search, the gene wasn't registerated in Gene Bank yet. And as we know, conserved domain region of esterase , G-X-S-X-G, wasn't discovered.$^{4)}$ And it is similar to Beta-lactamase. The DNA sequence of cloned esterase include an open reading frame consisting of 1170 bp, designated as EST-Y29, encoding a protein of 389 amino acids with a molecular mass of about 42.8 kDa. And amino acid sequence analysis revealed only a few identity (28%) to tile known esterases/lipases in the databases containing the conserved sequence motifs of esterases/lipases. when being comparison to other esterase revealed , this enzyme seems to be classified as a new member of esterase family. EST-Y29 was functionally overexpressed in a soluble form in E. coli with maximum conversion yield of (S)-ketoprofen at $65^{\circ}C$. This study demonstrates that functional screening combined with the sequential uses of restriction enzymes to exclude already known enzymes is a useful approach for isolating novel enzyme from a metagenome.

• 한국응용곤충학회지
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• 제35권1호
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• pp.74-79
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• 1996

배추좀나방의 deltamethrin에 대한 약제 저항성 기작을 알기 위하여 에스테라제의 활성과 조성을 분석하였다. 0.1$\mu\textrm{g}$의 deltamethrin으로 매 세대 선발하였을 때 선발세대의 진행에 따라 배추좀나방 4령충의 약제감수성은 줄었고 에스테라제 활성을 증가했다. Deltamethrin으로 선발된 또는 선발되지 않은 서로 다른 배추좀나방 집단들의 약제감수성과 에스테라제 활성간에 높은 상관을 보였으며 이들 요인들간에 상관계수는 0.9918(P=0.0082)로 정상관을 보였다. 전기영동(6% gel)의 결과 17개의 에스테라제 밴드가 분리되었다. Deltamethrin에 대해 선발된 집단들은 비선발 집단에 비해 적은 숫자의 에스테라제 밴드를 보여주었다. 그러나 4개 밴드(E3, E4, E11, E12)는 deltamethrin 선발집단에서만 나타난 밴드였다.

• Entomological Research
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• 제48권5호
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• pp.400-404
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• 2018

In this study, we investigated resistance to the organophosphates chlorpyrifos in Tunisian populations of Culex pipiens pipiens. Three field populations were collected from Northern and central Tunisia between 2003 and 2005 and used for the bioassays tests. Our results registered moderate and high levels of resistance to chlorpyrifos which ranged from 33.8 to 111. The chlorpyrifos resistant populations were highly resistant to propoxur indicated an insensitive acetylcholinesterase 1 (AChE 1). The highest frequency of AChE 1 resistant phenotypes (64%) was recorded in the most resistant population (sample # 1). Bioassays conducted in the presence of synergists showed that not esterases were involved as the resistance mechanism to chlorpyrifos. However, CYP450 was partly involved in the resistance of the most resistant sample (# 1). Starch electrophoresis showed that three esterases were present in studied samples: A2-B2, A4-B4 and B12. Results are discussed in relation to the selection pressure caused by insecticide treatments.

• Applied Biological Chemistry
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• 제31권3호
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• pp.241-248
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• 1988

서양종(西洋種) 꿀벌(Apis mellifera L)에 대(對)한 살충제의 독성(毒性) 및 해독능력(解毒能力)을 조사(調査)하고 농약한계사용량(農藥限界使用量) 결정(決定)에 기여(寄與)하기 위하여 7가지 대표적(代表的)인 살충제의 꿀벌에 대한 독성(毒性)및 해독효소(解毒酵素)의 활성(活性)을 조사(調査)하였다. 효소활성(酵素活性)은 해독효소(解毒酵素)로 알려진 microsomal oxidases, glutathione S-transferases, esterases 와 DDT-dehydrochlorinase를 조사(調査)했고 성충(成？)일별의 중장(中腸)을 사용(使用)하여 측정(測定)하였다. $LC_{50}$치(値)의 측정결과(測定決果) 공시(供試) 살충제중(殺？劑中) DDT가 58ppm으로 독성(毒性)이 가장 낮았고 EPN이 1.61ppm으로 독성(毒性)이 가장 강(强)했다. 준치사농도(準致死濃度)의 농약(農藥)이 성충(成？)일벌의 microsomal oxidase에 미치는 영향은 malathion 및 permethrin 처리(處理)가 aldrin epoxidase 활성(活性)을 저해(沮害)시켰고 N-demethylase 활성(活性)은 diazinon 처리구(處理區)에서 증대(增大)되었다. Ghtathione S-transferarse(DCNB conjugation) 활성(活性)은 diazinon과 permethrin 처리구(處理區)에서 증대(增大)되었다. Esterase는 malathion 및 permethrin 처리구(處理區)에서 ${\alpha}-NA$ esterase활성(活性)의 저해(沮害)를 보였고 diazinon처리구(處理區)에서 carboxylesterase활성(活性)이 증대(增大)되었으며 AChE 활성(活性)은 거의 영향(影響)이 없었다. DDT-dehy drochlorinase활성(活性)은 carbaryl 및 permethrin 처리구(處理區)에서 증대(增大)되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1999년도 임시총회 및 추계 학술발표회
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• pp.42.1-42
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• 1999

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.68-88
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• 2002

Phospholipase A$_2$ (s) are esterases that hydrolyze the sn-2 ester bond in phospholipids, releasing a fatty acid and a lysophospholipid. We previously showed that most PLA$_2$ activity in rabbit renal proximal tubule cells (RPTC) was Ca$\^$2+/-independent, localized to the endoplasmic reticulum (ER-iPLA$_2$), and inhibited by the specific Ca$\^$2+/-independent PLA$_2$ inhibitor bromoenol lactone (BEL).(omitted)

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.153-156
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• 2000

1. A. ficuum의 genomic library 검색을 통해 Axe 유전자를 포함하고 있는 5.0 kb의 XbaI DNA 절편을 cloning 했다. Cloning 된 절편의 부분 염기서열 결정 결과 약 1.4 kb의 AXE coding 부위를 확인했으며, cDNA cloning과 그 염기서열의 결정을 통해 AXE coding 부위 내에는 두 개의 intron 이 존재함이 확인되었다. 2. AXE coding 부위의 아미노산 잔기 서열 검색 결과 A. awamori의 AXE와 약 92%의 상동성과 95%의 유사성이 있음이 확인 되었다. 3. 약 900 kb의 AXE의 cDNA를 yeast의 YEp352 vector의 GAL1 promoter의 전사 방향으로 cloning한 후 발현시킨 결과 형질전환체에서 acetyl esterase 활성을 확인했으며, 활성도는 숙주균주에 비해 약 4-5배의 높은 OD unit로 나타내는 것을 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.155-162
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• 2020

Acetyl xylan esterase (AXE; E.C. 3.1.1.72) is one of the accessory enzymes for xylan degradation, which can remove the terminal acetate residues from xylan polymers. In this study, two genes encoding putative AXEs (LaAXE and BhAXE) were cloned from Lactobacillus antri DSM 16041 and Bacillus halodurans C-125, and constitutively expressed in Escherichia coli. They possess considerable activities towards various substrates such as p-nitrophenyl acetate, 4-methylumbelliferyl acetate, glucose pentaacetate, and 7-amino cephalosporanic acid. LaAXE and BhAXE showed the highest activities at pH 7.0 and 8.0 at 50℃, respectively. These enzymes are AXE members of carbohydrate esterase (CE) family 7 with the cephalosporine-C deacetylase activity for the production of antibiotics precursors. The simultaneous treatment of LaAXE with Thermotoga neapolitana β-xylanase showed 1.44-fold higher synergistic degradation of beechwood xylan than the single treatment of xylanase, whereas BhAXE showed no significant synergism. It was suggested that LaAXE can deacetylate beechwood xylan and enhance the successive accessibility of xylanase towards the resulting substrates. The novel LaAXE originated from a lactic acid bacterium will be utilized for the enzymatic production of D-xylose and xylooligosaccharides.

• 한국균학회지
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• 제25권4호통권83호
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• pp.320-329
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• 1997

병든 오이, 토마토, 딸기로부터 분리한 Botrytis cinerea을 Paul(1928)의 형태형(morphological phenotypes) 분류 기준에 따라 포자형, 균핵형, 균사형으로 나눌 때 대부분의 균주는 균핵형으로 나타났다. Benzimidazole 및 dicarboximide계 살균제에 대한 감수성 및 저항성 반응 차이는 형태형과는 무관하였다. 포자의 표면 구조를 주사형 전자현미경으로 관찰한 결과 모두 봉상으로 형태형 간에 차이가 없었다. 형태형 간 병원성을 비교할 때, 균사형의 균주가 가장 병원성이 높았으며, 포자형은 병원성이 다른 형보다 낮게 나타났다. 병원성과 곰팡이의 phenol oxidase, pectin methyl esterases (PME), amylases, cellulases, ureases, glucosidases 및 proteinases 활성과의 관계를 조사하기 위하여 형태형이 다른 선발된 균주들의 효소 활성을 조사한 결과, Phenol oxidase, ${\beta}-glucosidase$는 각 형태형 간에 차이가 없었으나, PME, amylase, cellulase, urease, proteinase의 활성은 각 형태형간에 차이를 나타내어 병원성과 이들 효소 활성의 관련성이 있었다.