• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.138.2-139
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• 2003

Grapevine leafroll-associated 1 virus (GLRaV-1) and Grapevine leafroll-associated 3 virus (GLRaV-3), member of the genus Ampelovirus, are important viral disease of grapevine in the world. these viruses transmitted only dicotyledonous host by vectors such as mealybugs and there is no suitable herbaceous host for virus. The diseased leaves turn yellowish or reddish depending on cultivars and viruses. Viruses are existed at low concentration and ununiformly distribution in grapevine. Using small-scale double-stranded RNA (dsRNA) extraction method, reverse transcription and polymerase chain reaction (RT-PCR) product of 1Kb long which encoded of coat protein (CP) gene for both viruses was successfully amplified with a specific primers. The RT-PCR product was cloned into the plasmid vector and its nucleotide sequences were determined from selected recombinant cDNA clones. Sequence analysis revealed that the CP of GLRaV-1 consisted of 969 nucleotide, which encoded 323 amino acid residues and CP of GLRaV-3 consisted of 942 nucleotide, which encoded 314 amino acid residues. The CP of GLRaV-1 and GLRaV-3 has 93.8％ and 98.7％ amino acid sequence identities, respectively.

• Korean Journal of Medicinal Crop Science
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• v.12 no.2
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• pp.135-140
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• 2004

Total RNAs were isolated from cultured roots of Scopolia parviflora, $poly(A)^+$ RNA was obtained through the mRNA purification, cDNA library of Hnh6h was constructed. Recombinant baculoviruses in Spodoptera frugiperda (Sf) cells were constructed by use of the transfer vector pBacPAK, which has the AcNPV sequence under the polyhedrin promoter. The expression vector carrying Hnh6h gene was transferred to S. parviflora and obtained transgenic hairy root lines. Our results confirmed the over expression of the H6H protein was used by anti-pBacPAK about cDNAs of S. parviflora. This study will served for production of tropane alkaloids by metabolic engineering.

• BMB Reports
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• v.40 no.2
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• pp.172-179
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• 2007

PCR-mediated recombination describes the process of in vitro chimera formation from related template sequences present in a single PCR amplification. The high levels of genetic redundancy in eukaryotic genomes should make recombination artifacts occur readily. However, few evolutionary biologists adequately consider this phenomenon when studying gene lineages. The cytosolic glyceraldehyde-3-phosphate dehydrogenase gene (GapC), which encodes a NADP-dependent nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase in the cytosol, is a classical lowcopy nuclear gene marker and is commonly used in molecular evolutionary studies. Here, we report on the occurrence of PCR-mediated recombination in the GapC gene family of Hibiscus tiliaceus. The study suggests that recombinant areas appear to be correlated with DNA template secondary structures. Our observations highlight that recombination artifacts should be considered when studying specific and allelic phylogenies. The authors suggest that nested PCR be used to suppress PCRmediated recombination.

• BMB Reports
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• v.43 no.8
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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.

• BMB Reports
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• v.35 no.5
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• pp.508-512
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• 2002

Phospholipase C-gamma-2 ($PLC{\gamma}2$) activation is a key signaling event for many cell functions. In order to delineate the pathways that lead to $PLC{\gamma}2$ activation, we devised a quick method for obtaining sufficient $PLC{\gamma}2$. We obtained the full-length cDNA for human $PLC{\gamma}2$ and expressed it in E. coli using the expression vector pT5T. To enhance the protein expression, tandem AGG-AGG arginine codons at the amino acid positions 1204-1205 were replaced by CGG-CGG arginine codons. The protein expression was detected in a Western blot analysis by both anti-$PLC{\gamma}2$ antibodies and the antibodies that are raised against the tripeptide epitope (Glu-Glu-Phe) tag that are genetically-engineered to its carboxyl terminal. Crude lysates that were prepared from bacteria that express $PLC{\gamma}2$ were found to catalyze the hydrolysis of phosphatidylinositol 4,5 bisphosphate. Similar to previous reports on $PLC{\gamma}2$ that is isolated from mammalian tissue, the recombinant enzyme was $Ca^{2+}$ dependent with optimal activity at 1-10 uM $Ca^{2+}$.

• Parasites, Hosts and Diseases
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• v.39 no.2
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• pp.133-141
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• 2001

A cDNA of 1.1 kb comprising the gene encoding the peroxiredoxin of Toxo-plasma gondii(TgPrx) has been cloned. The open reading frame of 591 Up was translated into a protein of 196 amino acids with a molecular mass of 25 kDa. Conserved 2 cysteine domains of Phe-Val-Cys-Pro and Glu-Val-Cys-Pro indicated TgPrx belonged to 2-Cys Prx families. TgPrx showed the highest homology with that of Arabidopsis thaliana by 53.9% followed by Entamoeba histolytica with 39.5% by the amino acid sequence alignment. Polyclonal antibody against recombinant TgPrx detected 25 kDa band in T. gondii without binding to host cell proteins TgPrx was located in the cytoplasm of T. gondii extracellularly or intracellularly by immunofluorescence assay. The expression of TgPrx was increased as early as 30 min after the treatment with artemisinin in the intracellular stage, while no changes in those of host Prx I and TgSOD. This result implies that TgPrx may function as an antioxidant protecting the cell from the attack of reactive oxygen intermediates. It is also suggested that TgPrx is a possible target of chemotherapy.

• Parasites, Hosts and Diseases
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• v.40 no.3
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• pp.131-138
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• 2002

The cyclophilins (Cyps) are family members of proteins that exhibit peptidylprolyl cis-trans isomerase (PPIase, EC 5.2.1.8) activity and bind the immunosuppressive agent cyclosprin A (CsA) in varying degrees. During the process of random sequencing of a cDNA library made from Giardia intestinalis WB strain, the cyclophilin gene (gicypl) was isolated. An open reading frame of gicyp1 gene was 576 nucleotides, which corresponded to a translation product of 176 amino acids (Gicypl). The identity with other Cyps was about 58-71%. The 13 residues that constituted the CsA binding site of human cyclophilin were also detected in the amino acid sequence of Gicypl, including tryptophan residue essential for the drug binding. The single copy of the gicypl gene was detected in the G. intestinalis chromosome by southern hybridization analysis. Recombinant Gicyp 1 protein clearly accelerated the rate of cis ${\rightarrow}$ trans isomerization of the peptide substrate and the catalysis was completely inhibited by the addition of $0.5{\;}{\mu}M$ CsA.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.11a
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• pp.35-39
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• 1997

Recent development of human genetics and techniques of gene transfer and expression have opened the way for investigating novel approaches based on the genetic modification of cells to treat both inherited and acquired diseases. This approach is referred to as gene therapy. Over the past few years, gene therapy has moved from the laboratory to phase I clinical trials. Although the clinical performance of gene transfer experiments is still in an early phase of development, the NIH of Health Recombinant DNA Advisory Comittee (RAC) has approved more than 150 protocols that involve gene transfer or putative gene therapy procedures in clinical settings. Many sectors of society in United States have participated in the design and formulation of these clinical trials through local Institutional Review Boards, the National Institutes of Health (NIH) RAC, the Chemotherapy Evaluation Program of the National Cancer institute, and the FDA. Currently, clinical trials involving gene modification are under way at many medical centers throughout the United Slates. The goals of these trials are as follows. (1) The design should be directed to short-term achievable goals. (2) Each clinical trial is best considered as an intermediate step in a multistep process. (3) The design should identify evaluable proximate endpoints for toxicity and for efficacy, (4) The potential benefits and possible risks for patients participating in these trial should be defined.

• Journal of Microbiology
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• v.42 no.3
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• pp.205-210
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• 2004

The sequence coding for carboxymethylcellulase (CMCase, CelC) was isolated from the DNA of Salmonella typhimurium URl. Comparison between the deduced amino acid sequence of CelC (368 amino acid residues, Molecular mass 41 kDa) and that of the previously published CMCase revealed that this enzyme belongs to the cellulase family 8 and D. The protein was overproduced in Escherichia coli using T7 expression system, and its activity was confirmed by CMC-SDS-PAGE. When the overexpressed CelC protein was tested on cellulose-type substrates, the recombinant protein is able to degrade cellulose-type substrates, such as CM-cellulose, xylan, avicel, lichenan, and laminarin. Optimal temperature and pH for enzyme activity were found to be 50$^{\circ}C$ and pH 6.5, respectively.

• The Microorganisms and Industry
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• v.19 no.2
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• pp.34-41
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• 1993

Industrial strain improvement is concerned with developing or modifying microorganisms used in production of commercially important fermentation products. The aim is to reduce the production cost by improving productivity of a strain and manipulating specific characteristics such as the ability to utilize cheaper raw materials or resist bacteriophages. The traditional empirical approach to strain improvement is mutation combined with selection and breeding techniques. It is still used by us to improve the productivity of organisms in amino acids, organic acids and enzymes production. The breeding of high L-lysine-producing strain Au112 is one of the outstanding examples of this approach. It is a homoserine auxotroph with AEC, TA double metabolic analogue resistant markers. The yield reaches 100 g/l. Besides, the citric acid-producing organism Aspergillus niger, Co827, its productivity reaches the advanced level in the world, is also the result of a series mutations especially with $^60Co{\gamma}$-radiation. The thermostable .alpha.-amylase producing strain A 4041 is the third example. By combining physical and chemical mutations, the strain A 4041 becomes an asporogenous, catabolite derepressed mutant with rifamycin resistant and methionine, arginine auxotroph markers. The .alpha.-amylase activity reaches 200 units/ml. The fourth successful example of mutation in strain improvement is the glucoamylase-producing strain Aspergillus niger SP56, its enzyme activity is 20,000 units/ml, 4 times of that of the parental strain UV-11. Recently, recombinant DNA approach provides a worthwhile alternative strategy to industrial strain improvement. This technique had been used by us to increase the thermostable .alpha.-amylase production and on some genetic researches.