• KSBB Journal
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• 제13권4호
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• pp.404-410
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• 1998

CHO 세포외 성장 및 생산성을 저해하는 엄포늄 이온의 동시 제거를 위해 PhJlhpsite~Gismondine 합성 zeolite가 alginate, cellulose acetate. dialysis membrane에 고정화된 흡착제가 개발되었다. 고정화 흡착체에 의한 암모늄 이온의 제거 효율 및 비에 따른 세표성장의 증진효과를 비교한 결과 최적의 고정화 흡착제로 membrane type이 선정되었다. 암모늄 이온의 제거 효파를 더욱더 명확하게 하고 고멸도의 세포 배양을 모사하가 위하여 8mM의 ammonium chloride를 첨가하고 membrane type 고정화 흡착제를 투여하여 암모늄 이온의 동시제거 효과를 조사한 결과 최대 세포 농도가 3배 이상 증가하였으며 생존율 역시 증가하였고 40%정도의 tPA 생산성 향상올 보여 주었다­. 이러한 증진 효과는 암모늄 이온의 고농도 시스템일수록 커졌다. 고정화 흡착제의 최적 투며 시기를 조사해본 결과 ammonium chlonde를 첨가하지 않았을 때 membrane type 고 정화 흡착제의 최적 투여 시기는 배양 시작 후 48시간이었고, 8mM의 ammonium chloride를 침가한 경우의 최적 투여 시기는 배양 시작 후 72시간이었다.

• 한국미생물·생명공학회지
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• 제36권1호
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• pp.12-20
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• 2008

세포배양 유래 생물의약품 생산 공정에서 다양한 바이러스가 오염된 사례가 있기 때문에 바이러스 안전성 검증이 필수적이다. MVM은 동물 세포주와 동물 세포 배양 공정에 오염되는 대표적인 바이러스이다. 세포배양 유래 생물의약품의 MVM 안전성을 확보하기 위해, 세포주, 원료물질, 제조공정, 완제품에서 MVM을 정량적으로 검출하고, 제조공정에서 MVM 제거 검증을 위한 시험법으로 활용이 가능한 real-time PCR 시험법을 확립하였다. MVM에 특이적인 primer를 선별하였으며, 형광염료 SYBR Green I을 사용하여 MVM DNA 정량 검출 시험법을 최적화하였다. 세포배양 법에 의한 감염역가와 비교한 결과 real-time PCR 민감도는 $6{\times}10^{-2}TCID_{50}/mL$이었다. 확립된 시험법의 신뢰성(reliability)을 보증하기 위해 시험법 검증을 실시한 결과 특이성(specificity)과 재현성(reproducibility)이 우수함을 확인하였다. 확립된 real-time PCR을 생물의약품 제조공정 검증에 적용할 수 있는지 확인하기 위하여 인위적으로 MVM을 오염시킨 CHO 세포에서 MVM검출 시험을 실시한 결과 MVM을 감염시킨 CHO 세포와 세포배양 상청액에서 MVM을 정량적으로 검출할 수 있었다. 또한 바이러스 필터 공정에서 MVM제거 효과를 감염역가 시험법과 비교 검증한 결과 더 높은 민감도로 빠른 시간에 동일한 결과를 얻을 수 있었다. 위와 같은 결과에서 확립된 MVM real-time PCR시험법은 생물의약품 안전성 보증을 위한 세포주 검증, 생물의약품 생산 공정 검증, 바이러스 제거 공정 검증 등에서 감염역가 시험법을 대신할 수 있는 신속하고, 특이성과 민감성이 우수한 시험법임을 확인하였다.

• BMB Reports
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• 제42권2호
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• pp.113-118
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• 2009

Despite the growing body of evidence suggesting a role for MsrA in antioxidant defense, little is currently known regarding the function of MsrB in cellular protection against oxidative stress. In this study, we overexpressed the mammalian MsrB and MsrA genes in Saccharomyces cerevisiae and assessed their subcellular localization and antioxidant functions. We found that the mitochondrial MsrB3 protein (MsrB3B) was localized to the cytosol, but not to the mitochondria, of the yeast cells. The mitochondrial MsrB2 protein was detected in the mitochondria and, to a lesser extent, the cytosol of the yeast cells. In this study, we report the first evidence that MsrB3 overexpression in yeast cells protected them against $H_2O_2$-mediated cell death. Additionally, MsrB2 overexpression also provided yeast cells with resistance to oxidative stress, as did MsrA overexpression. Our results show that mammalian MsrB and MsrA proteins perform crucial functions in protection against oxidative stress in lower eukaryotic yeast cells.

• BMB Reports
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• 제43권8호
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• pp.541-546
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• 2010

We utilized a mammalian expression system to purify and characterize autotaxin (ATX)/lysophospholipase D, an enzyme present in the blood responsible for biosynthesis of lysophosphatidic acid. The human ATX cDNA encoding amino acids 29-915 was cloned downstream of a secretion signal of CD5. At the carboxyl terminus was a thrombin cleavage site followed by the constant domain (Fc) of IgG to facilitate protein purification. The ATX-Fc fusion protein was expressed in HEK293 cells and isolated from conditioned medium of a stable clone by affinity chromatography with Protein A sepharose followed by cleavage with thrombin. The untagged ATX protein was further purified to essential homogeneity by gel filtration chromatography with a yield of approximately 5 mg/liter medium. The purified ATX protein was enzymatically active and biologically functional, offering a useful tool for further biological and structural studies of this important enzyme.

• 한국가금학회:학술대회논문집
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• 한국가금학회 1999년도 제16차 정기총회및학술발표회
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• pp.34-50
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• 1999

A cDNA encoding chicken interferon-gamma (chIFN-${\gamma}$) was amplified from P34, a CD4$^{+}$ T-cell hybridoma by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into pUC18. THe sequences of cloned PCR products were determined to confirm the correct cloning. Using this cDNA as probe, chicken genomic library from White Leghorn spleen was screened. Phage clones harboring chicken interferon-gamma (chIFN-${\gamma}$) were isolated and their genomic structure elucidated. The chIFN-${\gamma}$ contains 4 exons and 3 introns spanning over 14 kb, and follows the GT/AG rule for correct splicing at the exon/intron boundaries. The four exons encode 41, 26, 57 and 40 amino acids, respectively, suggesting that the overall structure of IFN-${\gamma}$ is evolutionairly conserved in mammalian and avian species. The 5’-untranslated region and signal sequences are located in exon 1. Several AT-rich sequences located in the fourth exon may indicate a role in mRNA turnover. The 5’-flanking region contains sequences homologous to the potential binding sites for the mammalian transcription factors, activator protein-1(AP-1) activator protein-2(AP-2) cAMP-response element binding protein(CREB), activating transcription factor(ATF), GATA-binding fator(GATA), upstream stimulating factor(USF), This suggests that the mechanisms underlying transcriptional regulation of chicken and mammalian IFN-${\gamma}$ genes may be similar.r.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2000년도 추계심포지움 및 학술발표회:바이오모니터링 기법을 이용한 환경위해성 평가
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• pp.90-90
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• 2000

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.927-930
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• 2009

• Archives of Pharmacal Research
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• 제19권4호
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• pp.251-257
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• 1996

The detection of many synthetic chemicals used in industry that may pose a genetic hazard in our environment is subject of great concern at present. In this respect, the genetic toxicity of fenpropathrin ((RS)-.alpha.-cyano-3-phenoxybenzyl-2,2,3,3-tetramethyl cyclopropane carboxylate, CAS No.:39514-41-8), a pyrethroid insecticide, was evaluated in bacterial gene mutation system, chromosome aberration in mammalian cell system and in vivo micronucleus assay with rodents. In bacterial gene mutation assay, no mutagenicity of fenpropathrin (62-$5000\mug/plate$) was observed in Salmonella typhimurium TA 98, 100, 1535 and 1537 both in the absence and in the presence of S-9 metabolic activaton system. In mammalian cell system using chinese hamster lung fibroblast, no clastogenicity of fenpropathrin was also observed both in the absence and in the presence of metabolic activation system in the concentration range of $7-28\mug/ml$. And also, in vivo micronucleus assay using mouse bone marrow cells, fenpropathrin also revealed no mutagenic potential in the dose range of 27-105 mg/kg body weight of fenpropathrin (i.p.). Consequently, no mutagenic potential of fenpropathrin was observed in vitro bacterial, mammalian mutagenicity systems and in vivo micronucleus assay in the dose ranges used in this experiment.

• Molecules and Cells
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• 제27권3호
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• pp.337-343
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• 2009

We developed a novel on-chip activity assay using protein arrays for quantitative and rapid analysis of transglutaminase activity in mammalian cells. Transglutaminases are a family of $Ca^{2+}$-dependent enzymes involved in cell regulation as well as human diseases such as neurodegenerative disorders, inflammatory diseases and tumor progression. We fabricated the protein arrays by immobilizing N,N'-dimethylcasein (a substrate) on the amine surface of the arrays. We initiated transamidating reaction on the protein arrays and determined the transglutaminase activity by analyzing the fluorescence intensity of biotinylated casein. The on-chip transglutaminase activity assay was proved to be much more sensitive than the $[^3H]putrescine$-incorporation assay. We successfully applied the on-chip assay to a rapid and quantitative analysis of the transglutaminase activity in all-trans retinoic acid-treated NIH 3T3 and SH-SY5Y cells. In addition, the on-chip transglutaminase activity assay was sufficiently sensitive to determine the transglutaminase activity in eleven mammalian cell lines. Thus, this novel on-chip transglutaminase activity assay was confirmed to be a sensitive and high-throughput approach to investigating the roles of transglutaminase in cellular signaling, and, moreover, it is likely to have a strong potential for monitoring human diseases.

• 대한수의학회지
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• 제42권1호
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• pp.55-64
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• 2002

HIV-1의 envelope glycoprotein은 중화항체에 의한 체액성 면역반응의 중요한 target으로 surface glycoprotein인 gp120과 transmembrane glycoprotein인 gp41로 이루어져 있다. gp120과 gp41의 ectodomain으로 이루어진 gp140 유전자를 PCR의 방법으로 증폭하고 Semliki Forest virus(SFV) 유래 expression system을 이용하여 mammalian 세포에서 발현하였다. 발현된 gp140은 natural HIV-1에서와 같이 oligomer를 형성하였다. 발현된 gp140을 정제하여 BALB/c 마우스에 접종하여 항체가 형성되었음을 확인하였다.