• KSBB Journal
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• 제26권5호
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• pp.427-432
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• 2011

In this study, a EXGA gene code for exo-β-1,3-glucanase from Aspergillus oryzae was overexpressed and secretory produced in Saccharomyces cerevisiae. To overexpress the β-1,3-glucanase, pGInu-exgA and pAInu-exgA plasmids having GAL10 and ADH1 promoter, respectively, and exoinulinase signal sequence (Inu s.s) were constructed and introduced in S. cerevisiae SEY2102 and 2805. The recombinant β-1,3-glucanase was successfully expressed and secreted into the medium and the β--1,3-glucanase activity in 2102/pGInu-exgA and 2102/pAInu-exgA strain were 5.01 unit/mL and 4.09 unit/mL, respectively. In the 2805/pGInu-exgA and 2805/pAInu-exgA strain, the β-1,3-glucanase activity showed 3.23 unit/mL and 3.22 unit/mL, respectively. Secretory efficiency in each strain reached 95% to 98%. Subsequently, the recombinant β1,3-glucanase was used for ethanol production. Ethanol productivity in 2102/pAInu-exgA strain was 0.83 g/L when pre-treated Laminaria japonica which has initial reducing sugar of 1.4 g/L was used as substrate. It is assumed that the polysaccharides of Laminaria japonica was effectively saccharified by recombinant β-1,3-glucanase, resulting in increase of ethanol productivity. These results suggested that recombinant β-1,3-glucanase was efficiently overexpressed and secreted in S. cerevisiae SEY2102 as host strain by using ADH1 promoter-Inu s.s system.

• 생명과학회지
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• 제14권3호
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• pp.429-434
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• 2004

Zymomonas mobilis 유래 levansucrase 유전자(levU)를 GAL1 promoter 하류에 연결시킨 pYES-levU와 GAL10 promoter 하류에 Kluyveromyces marxianus exoinulinase의 분비 신호서열(INU1 ss) 하류에 연결시킨 pYInu-levU를 각각 구축하였다. 이들 plasmid를 invertase 결손 변이주(suc2-$\Delta$9)인 S. cerevisiae SEY2102에 형질전환시켜 고활성 형질전환주를 선발하였다. 효모 형질전환주를 galactose 함유 배지로 배양한 결과, pYES-levU 함유 형질전환주인 경우 levansucrase의 총활성은 7.17U/ml이고, pYInu-levU 함유 형질전환주인 경우 6.61U/ml에 도달하였다. 발현된 levansucrase 약 50% 정도가 배지와 periplasmic space에 존재하였고, INU1 ss에 의한 분비효율 증가는 관찰할 수 없었다. 또한, 효모에서 발현된 재조합 levansucrase는 과당쇄화된 형으로 생산되는 것으로 보여진다.

• Journal of Microbiology and Biotechnology
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• 제5권4호
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• pp.224-228
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• 1995

Fed-batch fermentations were conducted to produce human lipocortin-I (LC1), a potential anti-inflammatory agent, from recombinant Sacchromyces cerevisiae carrying a galactose-inducible expression system. The cell growth, expression level of LC1, and the plasmid stability were investigated under various LC1 induction modes performed by three different galactose feeding strategies. Galactoe was fed to induce the expression of LCl from the beginning (initial induction) of culture or when the cell concentration reached 120 OD (mid-phase induction) or 300 OD (late induction). Among the three galactose-induction modes tested, the initial induction mode yielded the best result with respect to a final expression level of LC1. Fedbatch fermentation with initial induction mode produced LC1 at a conentration of 220 mg/l, which corresponded to 1.38- and 1.53-fold increases over those produced by mid-phase and late induction modes.

• 한국수정란이식학회지
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• 제33권3호
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• pp.129-137
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• 2018

Acute vascular rejection has been known as a main barrier occurring in a xenograted tissue of alpha 1,3-galactosyltransferase knock-out (GalT KO) pig into a non-human primate (NHP). Adenosine which is a final metabolite following sequential hydrolysis of nucleotide by ecto-nucleotidases such as CD39 and CD73, act as a regulator of coagulation, and inflammation. Thus xenotransplantation of CD39 and CD73 expressing pig under the GalT KO background could lead to enhanced survival of recipient NHP. We constructed a human CD39 and CD73 expression cassette designed for endothelial cell-specific expression using porcine Icam2 promoter (pIcam2-hCD39/hCD73). We performed isolation of endothelial cells (pAEC) from aorta of 4 week-old GalT KO and membrane cofactor protein expressing pig ($GalT^{-MCP/-MCP}$). We were able to verify that isolated cells were endothelial-like cells using immunofluorescence staining analysis with von Willebrand factor antibody, which is well known as an endothelial maker, and tubal formation assay. To find optimal condition for efficient transfection into pAEC, we performed transfection with GFP expression vector using four programs of nucleofection, M-003, U-023, W-023 and Y-022. We were able find that the program W-023 was optimal for pAEC with regard to viability and transfection efficiency by flow cytometry and fluorescent microscopy analyses. Finally, we were able to obtain $GalT^{-MCP/-MCP}/CD39/CD73$ pAEC expressing CD39 and CD73 at levels of 33.3% and 26.8%, respectively. We suggested that pACE isolated from $GalT^{-MCP/-MCP}$ pig might be provided as a basic resource to understand biochemical and molecular mechanisms of the rejections and as an alternative donor cells to generate $GalT^{-MCP/-MCP}/CD39/CD73$ pig expressing CD39 and CD73 at endothelial cells.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.237-244
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• 1994

The vector systems for the expression and secretion of human lipocortin-l (LC1) from Saccharomyces cerevisiae were constructed with GAL10 promoter and the prepro leader sequence of mating factor-$\alpha$1. They were further constructed to contain three different transcription terminators; GAL7 terminator, LCl terminator and a fused form of these two terminators. The expression and secretion levels of LCl were compared to investigate the effect of transcription terminators on the LCl gene expression. For the expression cassettes employing the GAL7 terminator or the terminator of fused form, the expression levels of LCl were measured by scanning the immunoreactive LCl protein bands, and were found to be 0.27 g/l and 0.32 g/l, respectively. The highest expression level of 0.54 g/l was obtained with the expression vector containing the LCl transcription terminator. In all expression cassettes, the majority of LCl proteins expressed were retained intracellularly, indicating a low secretion efficiency of about 5%. The high expression level of LCl was explained by the great content and stability of LCl mRNA transcribed from the LCl terminator-employing vector. The results of this study demonstrate that the LCl transcription terminator functions for the expression of LCl in S. cerevisiae better than the GAL7 terminator.

• Asian-Australasian Journal of Animal Sciences
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• 제8권5호
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• pp.449-454
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• 1995

The present study was conducted to assess gene expression of bacterial lacZ driven by the SV40 promoter at early developmental stages of bovine embryos. The lacZ gene was linearized with BamHI digestion and introduced into the pronucleus by microinjection at 20 hrs after the commencement of in vitro fertilization. Intact bovine blastocysts were not stained with X-Gal, suggesting that there is no endogenous beta-galactosidase activity in these blastocysts. In contrast, the bovine blastocyst cells microinjected with the lacZ gene exerted a characteristic greenish-blue color originating from the bacterial beta-galactosidase activity, albeit at a low rate, i.e. 2.1% of the total fertilized oocytes injected. It was concluded, therefore, that the lacZ gene driven by the SV40 promoter could be used for an indirect screening method in which the presence of transgene is evaluated from the product of transgene expression.

• 한국미생물·생명공학회지
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• 제36권1호
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• pp.49-54
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• 2008

인간 췌장 유래 pro-carboxypeptidase B(CPB) 유전자를 클로닝한 후 GAL10 promoter 하류에 Saccharomyces cerevisiae mating factor alpha-1 secretion signal $(MF{\alpha}-1)$과 연결하여 $MF{\alpha}1$-pro-CPB를 구축하였다. 구축된 plasmid $pY{\alpha}$-hproCPB(7.72 kb)를 S. cerevisiae 2805에 형질 전환시켰다. 재조합 인간 proCPB(hproCPB)는 galactose 유도로 S. cerevisiae에서 성공적으로 발현되었고, 배양상등액으로 분비되었다. SDS-PAGE와 western blot 분석에 의해, 정제된 hproCPB 단백질이 약 45.9kDa임을 확인하였다 S. cerevisiae $2805/pY{\alpha}$-hproCPB의 발효조 회분배양 시 trypsin 처리에 의해 pro영역을 제거한 후 hCPB의 세포외 활성은 60시간째에 10.16 unit/mL이었다. 또한 재조합 hCPB의 Km 값은 약 0.43 mM 이었다.

• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1151-1158
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• 2011

In this study, a galactooligosaccharide (GOS) was synthesized using active ${\beta}$-galactosidase (${\beta}$-gal) inclusion bodies (IBs)-containing Escherichia coli (E. coli) cells. Analysis by MALDI-TOF (matrix-assisted laser desorption/ionization-time of flight) mass spectrometry revealed that a trisaccharide was the major constituent of the synthesized GOS mixture. Additionally, the optimal pH, lactose concentration, amounts of E. coli ${\beta}$-gal IBs, and temperature for GOS synthesis were 7.5, 500 g/l, 3.2 U/ml, and $37^{\circ}C$, respectively. The total GOS yield from 500 g/l of lactose under these optimal conditions was about 32%, which corresponded to 160.4 g/l of GOS. Western blot analyses revealed that ${\beta}$-gal IBs were gradually destroyed during the reaction. In addition, when both the reaction mixture and E. coli ${\beta}$-gal hydrolysate were analyzed by high-performance thin-layer chromatography (HP-TLC), the trisaccharide was determined to be galactosyl lactose, indicating that a galactose moiety was most likely transferred to a lactose molecule during GOS synthesis. This GOS synthesis system might be useful for the synthesis of galactosylated drugs, which have recently received significant attention owing to the ability of the galactose molecules to improve the drugs solubility while decreasing their toxicity. ${\beta}$-Gal IB utilization is potentially a more convenient and economic approach to enzymatic GOS synthesis, since no enzyme purification steps after the transgalactosylation reaction would be required.

• 한국가축번식학회지
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• 제21권2호
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• pp.167-176
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• 1997

본 연구는 수정란을 수란우에 이식하기 이전에 형질전환가능 수정란을 선발할 수 있다면 형질전환동물의 생산에 크게 도움이 되므로 3.2 kb $\beta$-actin promoter (lacZ/n대) DNA를 미세주입하여 배반포기배에서의 발현을 확인하여 이들을 선발할 수 있는가를 규명하고자 하엿다. 채란된 난포란은 10%FBS, 5$\mu\textrm{g}$/ml LH, 0.5$\mu\textrm{g}$/ml FSH, 100 unit/ml penicillin 및 100 $\mu\textrm{g}$/ml streptomycin이 함유된 TCM199에 22~24 시간동안 체외성숙을 유도후 5$\mu\textrm{g}$/ml heparin으로 수정능획득을 유도한 1$\times$106 sperm/ml의 정자로 체외수정을 시켰다. 체외수정후 18~20시간째에 vortexing에 의해 과립막세포를 제거하고 원심분리시켜 자/웅전핵이 확인되는 수정란의 핵에 3~4 ng/${\mu}\ell$ lacZ/neo DNA를 미세주입하였다. 모든 수정란의 배양은 3 mg/ml BSA, 20${\mu}\ell$/ml NEM AMINO acids 및 40${\mu}\ell$/ml BME amino acids가 함유되어 있는 CR1aa 배양액에 neo/DNA로 transfected 된 BRL 단층에서 실시하였다. G418에 대한 적정농도를 찾기 위하여 정상적인 수정란에 0, 50, 100 및 200 $\mu\textrm{g}$/ml G418를 첨가하여 배양한 결과 8일째에 30.3%(44/145), 8.7%(13/150), 0.7%(1/151) 및 0% (0/134)의 수정란이 배반포기까지 발달하였다. 그래서 본 실험에서는 일정하게 100$\mu\textrm{g}$/ml G418을 첨가하여 배양하였다. 총 1,127개의 수정란을 미세주입후 G418 없는 배양액에서 710개 (63.0%)가 분할하였다. 미세주입후 48시간째에 2-세포기이상 분할된 수정란을 대조구 및 100$\mu\textrm{g}$/ml G418처리구를 무작위로 할당하여 배양하였으며, 또한 740개의 정상수정란도 같은 반복수로 배양을 실시하였다. 미세주입한 수정란은 8일 후 11.6%(26/255) 및 5.2% (14/267)가 대조구 및 G418 처리구에서 배반포기까지 발달하였으며 정상수정란은 27.2% (151/740)가 배반포기 배까지 발달하였다. 미세주입후 대조구에서는 23.1$\pm$2.6/70.7$\pm$4.7 (32.7%)의 할구가 $\beta$-Gal 활력을 보였고, 반면에 100$\mu\textrm{g}$/ml G418 처리구에서는 40.3$\pm$4.1/48.8$\pm$7.5 (82.6%)가 $\beta$-Gal 활력을 보였다. 비록 mosaic 형태로 외래유전자가 발현되었지만 대조구에서 87.0% (26/30개) 배반포기가 $\beta$-Gal 활력을 보인 반면, G418 처리구에서는 모든 배반포기가 $\beta$-Gal 활력을 보였다 (P<0.05). 그러나 대조구 및 G418 처리구의 ICM colony에서는 영양배엽과 내배엽을 제외한 epiblast에서는 확인되지 않았다. 그러나 이 결과로부터 $\beta$-actin promoter/lacZ gene이 integration되지 않는 것인지 또는 다만 염색 확인이 되지 않는 것인지를 판단할 수는 없다. 이상의 결과는 미세주입후 G418에서 배양한 배반포기배에서는 대부분의 할구에서 주입된 gene을 발현하고 있었으나 ICM colony에서는 특히 epiblast에서는 발현되지 않거나 침묵하고 있었다. 비록 G418 처리구에서 훨씬 더 높은 비율로 주입된 gene이 발현되고 있으나 총세포수는 유의적으로 감소하여 이후 형질전환동물의 생산과 ES like-cell의 설립에는 감소될 것으로 사려된다. 그러나 형질전환 수정란의 선발 및 형질전환동물의 생산능력에 관해서는 더 많은 연구가 필요하다고 사려된다.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.59.2-59.2
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• 2007

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