• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.4
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• pp.212-215
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• 2002

Tyrosinase transcript In the blood Is known as the marker of malignant melanoma and it has been often determined by using reverse transcription-polymerase chain reaction (RT-PCA) . However, after the PCR process, the quantification of amplified CDMA by the gel electrophoresis is not reliable and time-consuming. for this reason, we tried to quantify the PCR product using a cuvette-type biosensor, where the oligonucleotide probe was immobilized on the cuvette surface and the single strand CDMA, the denatured PCH product, was then hybridized onto the immobilized probe to give a response signal. The response was Immediate and takes 15 min to obtain a stable signal. The biosensor was much more sensitive comparing to the gel electrophoresis method. The quantification of PCR product using a cuvette-type biosensor was feasible and rapid.

• BMB Reports
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• v.30 no.3
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• pp.216-221
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• 1997

Changes in pathogenicity of old and successively-cultured isolates of Fusarium oxysporum f. sp. niveum have been observed and the concept that such cultures will become attenuated is generally accepted. However, the genetic basis for this phenomenon has not been studied. In an effort to identify a DNA marker closely linked to variations, DNA methylation was investigated both before and after the successive transfers of F. o. f. sp. niveum isolates on artificial media. A sector of mycelium in F. o. f. sp. niveum race 2 isolate (TXXID) which showed variation in pigmentation and colonial morphology occurred after 18 successive weekly transfers on potato dextrose agar (PDA). The sector characteristics were stable and did not change after more successive transfers. It was shown that DNA methylation preexists in ribosomal RNA gene (rDNA) of F. o. f. sp. niveum and that additional changes in DNA methylation occurred during successive culturing.

• Journal of Aquaculture
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• v.19 no.1
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• pp.40-46
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• 2006

Bacillus subtilis strain with highly active chitosanase was isolated from the intestine of Sebastiscus marmoratus (scorpion fish). It was named as Bacillus subtilis CH1 by morphological, biochemical and 165 rRNA gene analysis. The optimal conditions for chitosanase production were investigated. The optimum carbon and nitrogen sources for Bacillus stibtilis CH1 were 2% starch and 1% yeast extract respectively. Unlike other chitosanases, the expression of this chitosanase was not induced or slightly induced with chitosan. The chitosanase secreted into the medium were concentrated with ammonium sulfate precipitation and purified by gel permeation chromatography. The molecular weight of purified chitosanase was 30 kDa. The optimum pH and temperature of purified chitosanase were 5.5 and $60^{\circ}C$ respectively. The purified chitosanase was continuously thermostable at $40^{\circ}C$ and showed stable activity between pH 6.0 and 8.0. Chitosanase activity of Bacillus subtilis CH1 under optimum condition was 4.1 units/ml.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.838-843
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• 2005

Brain-derived neurotrophic factor (BDNF) is a small secretory protein and a member of the nerve growth factor (NGF) gene family. We cloned the flounder BDNF gene from a flounder brain cDNA library. The nucleotide sequence of the cloned gene showed an open reading frame (ORF) consisting of 810 bp, corresponding to 269 amino acid residues. The tissue distribution of flounder BDNF was determined by reverse transcription-polymerase chain reaction (RT-PCR) in brain, embryo, and muscle tissues. To express fBDNF using a eukaryotic expression system, we constructed the vector mpCTV-BDNF containing the fBDNF gene and transformed this vector into Chlorella ellipsoidea. Stable integration of introduced DNA was confirmed by PCR analysis of genomic DNA, and mRNA expression in C. ellipsoidae was confirmed by RT-PCR analysis.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.138-143
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• 1997

We have designed and constructed a gene encoding novel high essential amino acid encoding protein(HEAAE). The resultant DNA fragment was tested for in vitro and in vivo expression and then cloned into plant expression vector pBI121, under the control of the cauliflower mosaic virus 35S promoter. Agrobacterium tumefaciens, strain LBA4404, was subsequently transformed with this new construct and Nicotiana tabacum var. Xanthi transgenic plants were obtained. DNA analysis by Southern procedure confirmed the presence of the multi-copy number of genes in the transformed plants. Analysis of RNA and protein synthesized in these transgenic plants demonstrated the stable expression of this gene.

• YAKHAK HOEJI
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• v.45 no.6
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• pp.708-714
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• 2001

Many studies have provided evidences that hepatitis B surface antigen (HBsAg) including preS region could be an ideal candidate for a new hepatitis B virus (HBV) vaccine with higher efficacy. We established CHO cell lines, IY-CHO-2 and IY-CHO-11 expressing high levels of HBsAg containing preS2 and S protein by stable transfection method. These cell lines expressed the correct size (about 1 kb in length) of HBsAg mRNA as expected. The purified protein from the culture supernatants of the clones showed the same sizes as those expressed in native hepatitis B virus (24 kDa, 27 kDa, 34 kDa and 36 kDa). Antibody productivity of CHO-derived HBsAg protein at lower dose challenge was higher than the protein containing S region alone expressed in yeast system. These results indicate that CHO-derived HBsAg protein containing preS2 and S region can be effectively used for a better immune response as a HBV vaccine.

• Bulletin of the Korean Chemical Society
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• v.4 no.3
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• pp.133-139
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• 1983

To understand the importance of Y-base adjacent to the anticodon stabilizing codon-anticodon interaction, a study has been undertaken for the model compound involving the interaction between Y-base and anticodon as well as the participation of water molecule by calculating the conformational free energy using an empirical potential function. We restrict our analysis to sites directly associated with Y-base by varying only the backbone torsion angles of Y-base. The hydration and $Mg^{+2}$ binding effects on the conformational stability of Y-base are calculated and discussed. The free Y-base is proved to be less stable than the hydrated one. The free energy change due to the hydration of Y-base amounts to -119.5 kcal/mole, in which the conformational energy change is -142.4 kcal/mole and the configurational entropy change is -76.9 e. u. It is found that the water molecules bound to Y-base and $Mg^{+2}$ contribute to the conformation of Y-base dominantly.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.49-54
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• 2018

To artificially enhance antimicrobial peptide expression in Bombyx mori, we constructed genetically engineered silkworms overexpressing Rel family transcription factor. The truncated BmRelish1 (BmRelish1t) gene contained a Rel homolog domain (RHD), nuclear localization signal (NLS), acidic and hydrophobic amino acid (AHAA)-rich region, and death domain (DD), but no ankyrin-repeat (ANK) domain. The BmRelish1t gene was controlled by B. mori cytoplasmic actin 3 promoter in the PiggyBac transposon vector. Chromosome analysis of G1 generations of a transgenic silkworm with EGFP expression confirmed stable insertion of BmRelish1t. BmRelish1t gene overexpression in transgenic silkworms resulted in higher mRNA expression levels of B. mori antimicrobial peptides such as lebocin(~20.5-fold), moricin(~8.7-fold), and nuecin(~17.4-fold) than those in normal silkworms.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.49-49
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• 2001

To elucidate overall changes in DNA methylation that occurs by inappropriate epigenetic control during ageing, we compared fetal bovine fibroblasts and their aged neomycin-resistant versions using bisulfite-PCR technology. Reduction in DNA methylation was observed in euchromatic repeats (18S-rRNA/art2) and promoter regions of sing1e-copy genes (the cytokeratin/-lactoglobulin/interleukin-13 genes). Contrastingly, a stable maintenance of DNA methylation was revealed in various heterochromatic sequences (satellite I/IIalphoid and Bov-B). The differential inheritance modes of DNA methylation was confirmed through the analysis of individual neomycin-resistant clones. These global, multi-loci analyses provide evidence on the tendency of differential epigenetic modification between genomic DNA regions during ageing.

• Journal of Marine Bioscience and Biotechnology
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• v.16 no.1
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• pp.55-62
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• 2024

Various antimicrobial peptides (AMPs) from microalgae have shown antibacterial, antiviral, antifungal, anticancer, and antioxidant effects, and play crucial roles in medical applications, aquaculture-related disease management, and the food industry. Magainin 2 (MAG2), an AMP, exhibits high antibacterial and antitumor activity, necessitating an efficient recombinant expression system for low-cost, large-scale production. To enhance MAG2 secretion efficiency in Chlorella, we constructed the SS:MAG2:His vector using the known Chlamydomonas reinhardtii CA1 signal sequence (SS) and obtained a stable transformant via an Agrobacterium-mediated transformation method and RT-qPCR. ELISA results revealed that the MAG2 content secreted into the medium by the SS:MAG2:His transformants increased proportionally with mRNA expression. These findings offer a strategy for high MAG2 secretion in the Chlorella vulgaris platform, potentially minimizing downstream processing costs.