• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.9-12
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• 1996

In order to produce the single chain precursor of a novel human insulin analogue, (B30-Homoserine) insulin, the fermentative behaviors of Escherichia coli JM103 were studied, which harbors pKBA plasmid carrying a hybrid gene in which the gene for a single chain precursor was fused with lacZ gene under tac promoter. The maximal induction of gene expression was achieved when more than 0.05 mM of isopropyl-$\beta$-D-thiogalactopyranoside(IPTG) was supplemented to fermentation medium after 4 h cultivation of E. coli, and followed by longer than 2-h fermentation. The hybrid protein of the single chain insulin precursor was isolated from cytoplasmic inclusion bodies by dissolving in 8M urea solution, and purified through DEAE-Sephacel and Sephadex G-200 column chromatographies with a recovery of 35%. The finally purified hybrid protein showed a single band on sodium dodecyl sulfate-polyacrylamide gel.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.168-173
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• 2009

Human follicle-stimulating hormone (hFSH) is a pituitary glycoprotein that regulates follicular development and ovulation. Clinically, hFSH has been used to induce follicular growth in infertile women. The hormone is composed of heterodimers, including a common ${\alpha}$ subunit among the gonadotropin family and a hormone-specific ${\beta}$ subunit. Since assembly of the heterodimer is a rate-limiting step in the production of functional hFSH, transgenic clone cows carrying a single-chain hFSH transgene may efficiently produce functional hormone. Genes encoding the ${\alpha}$ and ${\beta}$ subunits of hFSH were linked using the C-terminal peptide sequence from the ${\beta}$ subunit of human chorionic gonadotropin. Bovine fetal fibroblasts were transfected with the gene construct, including the goat ${\beta}$-casein promoter and a single-chain hFSH coding sequence. Transfected fibroblasts were transferred into enucleated oocytes, and individual nuclear transfer (NT) embryos developed to the blastocyst stage were analyzed for the transgene by polymerase chain reaction. Seventy eight blastocysts (30.8%) were developed from 259 reconstructed embryos. Among these blastocysts, the hFSH gene was detected in 70.8% (34/48) of the embryos. Subsequent transfer of hFSH-transgenic clone embryos to 31 recipients results in 11 (35.5%) early pregnancies. However, all fetuses were lost before reaching day 180 of gestation. The results from this study demonstrated that bovine NT embryos carrying single-chain hFSH could be produced, and further extensive studies in which NT embryos are transferred to more recipients may give rise to single chain hFSH-transgenic cows for biomedical applications.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.144-149
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• 2001

For the production and purification of a single chain human insulin precursor, four types of fusion peptides $\beta$-galactosidase (LacZ), maltose binding protein (MBP), glutathione-S-transferase (GST), and (His)(sub)6-tagged sequence (HTS) were investigated. Recombinant E. coli harboring hybrid genes was cultivated at 37$\^{C}$ for 1h, and gene induction occurred when 0.2mM of isopropyl-D-thiogalactoside (IPTG) was added to the culture broth, except for E. coli BL21 (DE3) pLysS harboring a pET-BA cultivation with 1.0mM IPTG, followed by a longer than 4h batch fermentation respectively. DEAE-Sphacel and Sephadex G-200 gel filtration chromatography, amylose affinity chromatography, glutathione-sepharose 4B affinity chromatography, and a nickel chelating affinity chromatography system as a kind of immobilized metal ion affinity chromatography (IMAC) were all employed for the purification of a single chain human insulin precursor. The recovery yields of the HTS-fused, GST-fused, MBP-fused, and LacZ-fused single chain human insulin precursors resulted in 47%, 20%, 20%, and 18% as the total protein amounts respectively. These results show that a higher recovery yield of the finally purified recombinant peptides was achieved when affinity column chromatography was employed and when the fused peptide had a smaller molecular weight. In addition the pET expression system gave the highest productivity of a fused insulin precursor due to a two-step regulation of the gene expression, and the HTS-fused system provided the highest recovery of a fused insulin precursor based on a simple and specific separation using the IMAC technique.

• Clinical and Experimental Reproductive Medicine
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• 제21권3호
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• pp.281-284
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• 1994

Sex determination in genomic DNA from human blood leucocytes was performed by amplification of human Y chromosome-specific DNA sequences using PCR technique. A clear DNA fragment(154 nucleotides long) was appeared only in the male genomic DNA, but no specific band was observed in the case of female genomic DNA and negative control. To know the sensitivity of this method, the amplification reaction was performed in genomic DNA diluted to 2pg equivalent to the amonut present in the single human cell, and clear band also observed. The PCR amplification was so succesfully performed in the single leucocyte separated from human blood using micromanipulator that this techniqe is assumed to be applied to single blstomere before embryo transfer.

• BMB Reports
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• 제30권3호
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• pp.177-181
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• 1997

We constructed a single-chain immunoglobulin in which the carboxyl end of the heavy chain variable domain is covalently joined to the amino terminus of the light chain variable domain via peptide linker and the carboxyl end of the light chain variable domain is linked to human ${\gamma}1$ Fc region through the hinge region. The molecule was expressed in Chinese hamster ovary cells, assembled into a dimeric molecule and secreted into the culture medium. The dimeric molecule (2E11) was purified from the culture supernatant by affinity chromatography on Protein G-Sepharose column. The size of the unreduced or reduced protein was the expected molecular weight of approximately 120 or 60 kDa, respectively, as assessed by SDS-polyacrylamide gel electrophoresis. The antigen-binding affinity of 2E11 was almost the same as that of a native antibody counterpart (CS131A), suggesting that the single-chain immunoglobulin may function like a native antibody.

• Archives of Pharmacal Research
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• 제16권4호
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• pp.271-275
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• 1993

In order to prepare a novel human insulin analogue suhbstituted with homoserine at B$^{30}$ / position, (B$^{30}$ /-homoserine) human insulin, a synthetic gene was designed by linking directly a gene for B chain with that for A chain. This gene was constructed by enzymatic joining of 10 different synthetic oligonucleotides, and then inserted at the polylinker region of pUC19 plasmid. To achieve a high level of gene expression, the gene fusion technique region of pUC19 plasmid. To achieve a high level of gene expression, the gene fusion technique was employed using amino terminal regions of lacZ gene up to Clal or hpal, and either of them has been located under tac promoter. The chemical induction of these fused genes by isopropyl-.betha.-D-thiogalactopyranoside (IPTG) gave a satisfactory level of expression in Escherichia coli harboring the ocnstructed plasmids. It was observed that the fused gene product as a single chain insulin precusor was produced more than 30% of total cell protein of E. coli as a form of inclusion body.

• 미생물학회지
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• 제51권2호
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• pp.115-125
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• 2015

단일클론항체 AP64 IgM은 인간의 급성 비임파성 골수암(ANLL) 세포주 HL60에 결합하며 쥐의 ANLL 세포에도 교차결합(cross-react)한다. 또한 complement에 의해 매개되어지면 골수암 억제효과를 나타낸다. 본 연구에서는 RT-PCR에 의해 AP64 IgM을 분비하는 하이브리도마의 $V_H$ 및 $V_L$ cDNA로부터 유래된 재조합 single-chain variable domain fragment (ScFv)를 제조하였다. $V_H$ 및 $V_L$은 15개 아미노산으로 구성된 linker $(G_4S)_3$으로 연결되었다. 재조합 ScFv는 Escherichia coli BMH 71-18에서 single polypeptide chain으로 발현되었다. Periplasmic extract를 $Ni^+$-NTA-agarose affinity column에 가하여 발현된 재조합 ScFv를 정제하였으며 westernblot으로 정제된 단백질을 탐지하였다. 정제된 재조합 ScFv는 AP64 IgM 모항체가 탐지하는 항원과 같은 HL60 세포의 표면항원(약 30 kDa)을 인지하였다. 그러나 HL60의 표면항원에 대한 ScFv의 결합력은 AP64 IgM 모항체보다 낮아서 추후 이에 대한 개선이 필요하다. 종합하여 볼 때 HL60 세포주에 특이적인 재조합 ScFv는 진단 또는 치료목적으로 유용한 생물학적 제재가 될 수 있을 것이다.

• 대한화학회지
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• 제49권6호
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• pp.537-545
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• 2005

• IMMUNE NETWORK
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• 제12권1호
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• pp.33-39
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• 2012

Background: Therapeutic approaches using monoclonal antibodies (mAbs) against complement regulatory proteins (CRPs:i.e.,CD46,CD55 and CD59) have been reported for adjuvant cancer therapy. In this study, we generated a recombinant 1E8 single-chain anti-CD59 antibody (scFv-Fc) and tested anti-cancer effect.by using complement dependent cytotoxicity (CDC). Methods: We isolated mRNA from 1E8 hybridoma cells and amplified the variable regions of the heavy chain (VH) and light chain (VL) genes using reversetranscriptase polymerase chain reaction (RT-PCR). Using a linker, the amplified sequences for the heavy and light chains were each connected to the sequence for a single polypeptide chain that was designed to be expressed. The VL and VH fragments were cloned into the pOptiVEC-TOPO vector that contained the human CH2-CH3 fragment. Then, 293T cells were transfected with the 1E8 single-chain Fv-Fc (scFv-Fc) constructs. CD59 expression was evaluated in the prostate cancer cell lines using flow cytometry. The enhancement of CDC effect by mouse 1E8 and 1E8 scFv-Fc were evaluated using a cytotoxicity assay. Results: The scFv-Fc constructs were expressed by the transfected 293T cells and secreted into the culture medium. The immunoreactivity of the secreted scFv-Fc construct was similar to that of the mouse 1E8 for CCRF-CEM cells. The molecular masses of 1E8 scFv-Fc were about 120 kDa and 55 kDa under reducing and non-reducing conditions, respectively. The DNA sequence of 1E8 scFv-Fc was obtained and presented. CD59 was highly expressed by the prostate cancer cell line. The recombinant 1E8 scFv-Fc mAb revealed significantly enhanced CDC effect similar with mouse 1E8 for prostate cancer cells. Conclusion: A 1E8 scFv-Fc construct for adjuvant cancer therapy was developed.

• Clinical and Experimental Pediatrics
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• 제53권2호
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• pp.129-135
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• 2010

Human rhinoviruses (HRVs) is a nonenveloped, single stranded RNA virus belonging to the family Picornavirudae. Transmission by direct contact such as hand-to-hand, hand-to-nose, and hand-to-eye has been readily demonstrated in experimental settings. HRV are the most frequent causes of common cold infection, however, they are also known to replicate in the lower respiratory tract and associated with more severe respiratory illnesses such as asthma. New technique such as reverse transcriptase polymerase chain reaction and molecular typing in HRV has been developed and our understanding of the importance of these respiratory viruses. HRVs consisted of 101 serotypes that are classified into groups A and B according to sequence variations. And there is a newly identified set of HRVs, called Group C, and it is currently under investigation. In recent study using PCR techniques, HRVs accounted for approximate 50-80% of common colds and 85 % of childhood asthma exacerbations and in more than half of adult exacerbations. However, the mechanisms of HRV- induced asthma exacerbations are poorly understood. This review discusses the association between HRVs and childhood asthma.