• Journal of Photoscience
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• v.4 no.3
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• pp.141-145
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• 1997

Polymerase chain reaction(PCR) was conducted with a pea cDNA library using two primers synthesized from homology analysis of amino acid sequences for animal and plant cytosolic FBPases. A PCR product with 650 bp long was cloned into pGEM-T vector and sequenced. The deduced amino acid sequence of the cDNA fragment was 98, 91, and 85% homologous with those of cytosolic FBPases from spinach, sugarbeet, and sugarcane, respectively. It was 51% homologous with amino acid sequence of FBPase from pea chloroplasts. Northern blot analysis was proceeded with the cDNA clone resulting that 1.2 kb transcript was highly expressed in light-grown pea leaves but almost not expressed in dark-grown etiolated pea seedlings. When peas grown in the light for 10 days were transferred to darkness, the transcript was gradually decreased with dark treatment, indicating that the expression of the enzyme was induced by continuous white light but suppressed by dark treatment. Pea cytosolic FBPase was highly expressed in leaves with trace amounts in stems. but almost not expressed in roots.

• Korean Journal of Microbiology
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• v.40 no.3
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• pp.226-229
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• 2004

Histone deacetylase (HDAC) removes acetyl group in lysine residue of histone protein, which is transferred by histone acetylase. HDAC is important in the stabilization and regulation of gene expression in eukaryotic organisms. PCR has been carried out to clone HDAC genes using cDNA library and genomic DNA as the templates from Ganoderma lucidum isolated in Korea. One 470 bp cDNA gene fragment, and 3 genomic HDAC fragments (585 bp, 589 bp, 630 bp) were amplified. When their deduced amino acid sequences were compared with other fungal HDACs, they showed 59-72％ homology.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.166-166
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• 2008

The tidal flat of Korea is one of the most dynamic areas in terms of sediment erosion and deposition. Tidal flats provide important food resources, ecological niche for diverse organisms and have functional role of bioremediation by mineralizing organic matters. Generally, microbes are essential constituent for biochemical transformations, such as mineralization of organic matters and biodegradation of pollutants. Understanding microbes in tidal flat sediment is necessary to understand these processes. In order to understand role of microbes in tidal flat, this study investigated prokaryotic communities by several methods such as clone library, DGGE, and pyrosequencing. In addition, quantification of microorganisms and isolation biodegrading bacteria were investigated in tidal flats of Western Coast.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.440-446
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• 2006

To investigate flowering related genes in winter-type oilseed rape (Brassica napus L. cv. Tammi), differentially expressed genes were isolated from leaves of the plant after low temperature treatment which is requirements for floral induction. As a result of suppression subtractive hybridization (SSH), 288 clones were randomly selected from SSH library. Using reverse Northern blot analysis, 150 of 288 clones were identified to be differentially expressed. Out of these 150 clones, 45 clones showed very high identities with the known genes. Four clones showed very high identities over 90% with metallothionein-like gene that is related to flowering-induced genes. Of these 4 clones, the cDNA clone, rfs-13, revealed high identity with meotallothionein-like protein in Arabidopsis thaliana (98%) and Brassica compestris (89%). Furthermore, gene expressed in immature flower stages was confirmed by Northern blot analysis.

• Journal of Plant Biology
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• v.32 no.2
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• pp.67-78
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• 1989

Hybridization of DNA isolated from leaves of Russet Burbank potato with tomato cDNA as a probe revealed the presence of about ten inhibitor 1 genes in the genome. Screening of a genomic library of Russet Burbank potato resulted in isolation of seven different genomic clones carrying inhibitor I genes. One of the genomic clones, clone 2, contained two EcoRI fragments of 3.4 and 1.8 kb in size, respectively, which were hybridized with the probe. The nucleotide sequence of parts of the hybridizing EcoRI fragments revealed that they contain a complete gene which codes for an open reading frame of 107 amino acids. It is interrupted by two intervening sequences of 502 and 493 bp, situated at the positions of codons 17 and 43, respectively, of the open reading frame. Putative regulatory sequences, TATAAA and CCACT, were found at the 5' flanking region. In addition, a copy of a 100 bp repeat found at a tomato inhibitor I gene was identified.

• Journal of Ginseng Research
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• v.19 no.1
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• pp.51-55
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• 1995

The DNA fragment containing ginseng ribulose-1,5-bisphosphate carboxytase/oxygenase large subunit(rbcL) gene was cloned from the ginseng chloroplast EcoRl library by colony lift hybridization with tobacco rbcL gene probe. From the screened clone, the DNA fragment containing ginseng rbcL gene was digested with several restriction enzyme and analyzed by Southern blot hybridization for the construction of restriction map. The ginseng rbcL gene fragment was subcloned in pBluescript II SK + vector and sequence analysis was performed. The nucleotide sequence of ginseng rbcL gene was compared with those of petunia, tobacco, alfalfa, rice and barley, which showed a homology of 93.1%, 95.2%, 90.5%, 85.5% and 84.3%, respectively.

• Journal of Life Science
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• v.24 no.11
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• pp.1187-1192
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• 2014

Pepper, consumed as a typical spice food around world, is mainly cultivated in warm countries, including Korea, China, and Mexico. Phytophthora capsici is a pathogen on several economically important crops, including pepper. The oomycete attacks the roots, stems, leaves, and fruit of the host plants. To understand the molecular mechanisms underlying development of the disease, the genes expressed during pepper-P. capsici interaction were explored by analyzing expressed sequence tags (ESTs). A cDNA library was constructed from total RNA extracted from pepper leaves challenged with P. capsici for three days, resulting in an early stage of symptom development for comparable interaction. A comprehensive analysis of single-pass sequencing of 5,760 randomly selected cDNA clones extracted 5,148 high-quality entries for contig assembly, which generated 2,990 unigenes. A homology search of the unigenes with BLASTX resulted in 2,409 matches, of which 606 showed classified functional catalogs.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.888-897
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• 2009

Lipase diversity in glacier soil was assessed by culture-independent metagenomic DNA fragment screening and confirmed by cell culture experiments. A set of degenerate PCR primers specific for lipases of the hormone-sensitive lipase family was designed based on conserved motifs and used to directly PCR amplify metagenomic DNA from glacier soil. These products were used to construct a lipase fragment clone library. Among the 300 clones sequenced for the analysis, 201 clones encoding partiallipases shared 51-82% identity to known lipases in GenBank. Based on a phylogenetic analysis, five divergent clusters were established, one of which may represent a previously unidentified lipase subfamily. In the culture study, 11 lipase-producing bacteria were selectively isolated and characterized by 16S rDNA sequences. Using the above-mentioned degenerate primers, seven lipase gene fragments were cloned, but not all of them could be accounted for by the clones in the library. Two full-length lipase genes obtained by TAIL-PCR were expressed in Pichia pastoris and characterized. Both were authentic lipases with optimum temperatures of ${\le}40^{\circ}C$. Our study indicates the abundant lipase diversity in glacier soil as well as the feasibility of sequence-based screening in discovering new lipase genes from complex environmental samples.

• IMMUNE NETWORK
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• v.12 no.4
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• pp.155-164
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• 2012

It is well established that blocking the interaction of EGFR with growth factors leads to the arrest of tumor growth, resulting in tumor cell death. ER414 is a human monoclonal antibody (mAb) derived by guided selection of the mouse mAb A13. The ER414 exhibited a ~17-fold lower affinity and, as a result, lower efficacy of inhibition of the EGF-mediated tyrosine phosphorylation of EGFR when compared with mAb A13 and cetuximab. We performed a stepwise in vitro affinity maturation to improve the affinity of ER414. We obtained a 3D model of ER414 to identify the amino acids in the CDRs that needed to be mutated. Clones were selected from the phage library with randomized amino acids in the CDRs and substitution of amino acids in the HCDR3 and LCDR1 of ER414 led to improved affinity. A clone, H3-14, with a ~20-fold increased affinity, was selected from the HCDR3 randomized library. Then three clones, ER2, ER78 and ER79, were selected from the LCDR1 randomized library based on the H3-14 but did not show further increased affinities compared to that of H3-14. Of the three, ER2 was chosen for further characterization due to its better expression than others. We successfully performed affinity maturation of ER414 and obtained antibodies with a similar affinity as cetuximab. And antibody from an affinity maturation inhibits the EGF-mediated tyrosine phosphorylation of EGFR in a manner similar to cetuximab.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.73-79
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• 2019

A novel esterase gene (est7S) was cloned from an enriched metagenomic library derived from an oil-spill area. The gene encoded a protein of 505 amino acids, and the molecular mass of the Est7S was estimated to be 54,512 Da with no signal peptide. Est7S showed the highest identity of 40% to an esterase from a sludge metagenome compared to the characterized enzymes with their properties, although it showed 99% identity to a carboxylesterase in the genome sequence of Alcanivorax borkumensis SK2. Est7S had catalytic triad residues, Ser183, Glu312, and His420, and the GESAG motif in most family VII lipolytic enzymes. Est7S was purified from the crude extract of clone SM7 using Sephacryl S-200 HR and HiTrap Q column chromatographies. The purified Est7S was optimally active at $50^{\circ}C$ and pH 10.0. Est7S showed a high specific activity of 366.7 U/mg protein. It preferred short length esters, particularly p-nitrophenyl acetate, efficiently hydrolyzed R- and S-enantiomers of methyl-3-hydroxy-2-methylpropionate, and glyceryl tributyrate. These properties of Est7S may provide potential merits in biotechnological applications such as detergent and paper processing under alkaline conditions.