• BMB Reports
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• v.42 no.1
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• pp.53-58
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• 2009

The methyl-directed mismatch repair (MMR) mechanism has been extensively studied in vitro and in vivo, but one of the difficulties in determining the biological relationships between the MMR-related proteins is the tendency of MutL to self-aggregate. The properties of a stable MutL homologue were investigated using a thermostable MutL (TmL) from Thermotoga maritima MSB8 and whose size exclusion chromatographic and crosslinking analyses were compatible with a dimeric form of TmL. TmL underwent conformational changes in the presence of nucleotides and single-stranded DNA (ssDNA) with ATP binding not requiring ssDNA binding activity of TmL, while ADPnP-stimulated TmL showed a high ssDNA binding affinity. Finally, TmL interacted with the T. maritima MutS (TmS), increasing the affinity of TmS to mismatched DNA base pairs and suggesting that the role of TmL in the formation of a mismatched DNA-TmS complex may be a pivotal observation for the study of the initial MMR system.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.4
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• pp.145-148
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• 2004

In this study, a DNA chip with a microelectrode array was fabricated using microfabrication technology. Several probe DNAs consisting of mercaptohexyl moiety at their 5' end were immobilized on the gold electrodes by a DNA arrayer. Then target DNAs were hybridized and reacted with Hoechst 33258, which is a DNA minor groove binder and electrochemically active dye. Linear sweep voltammetry or cyclic voltammetry showed a difference between target DNA and control DNA in the anodic peak current values. It was derived from Hoechst 33258 and concentrated at the electrode surface through association with the formed hybrid. This suggested that this DNA chip could recognize the sequence specific genes.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.198-205
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• 2010

Background: A crucial limitation of DNA vaccines is its weak immunogenicity, especially in terms of eliciting antibody responses in non-human primates or humans; therefore, it is essential to enhance immune responses to vaccination for the development of successful DNA vaccines for humans. Methods: Here, we approached this issue by evaluating interleukin-7 (IL-7) as a genetic adjuvant in cynomolgus monkeys immunized with multigenic HCV DNA vaccine. Results: Codelivery of human IL-7 (hIL-7)-encoding DNA appeared to increase DNA vaccine-induced antibody responses specific for HCV E2 protein, which plays a critical role in protecting from HCV infection. HCV-specific T cell responses were also significantly enhanced by codelivery of hIL-7 DNA. Interestingly, the augmentation of T cell responses by codelivery of hIL-7 DNA was shown to be due to the enhancement of both the breadth and magnitude of immune responses against dominant and subdominant epitopes. Conclusion: Taken together, these findings suggest that the hIL-7-expressing plasmid serves as a promising vaccine adjuvant capable of eliciting enhanced vaccine-induced antibody and broad T cell responses.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.350-353
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• 2009

Peanut (Arachis hypogaea) often causes severe allergic reactions in sensitive people. Agglutinin is known to be one of the allergenic proteins in peanut. A polymerase chain reaction (PCR) method was developed to detect peanut ingredients in food using a primer pair corresponding to the agglutinin gene. This primer pair enabled PCR amplification of specific regions of agglutinin DNA from peanut, but not from 11 other nuts, beans, and cereals (pistachio, almond, sunflower seed, pine nut, walnut, soybean, black bean, kidney bean, azuki bean, rice, and black rice). The proposed PCR method successfully identified all of the 6 processed foods containing peanut whereas 13 other processed foods, which don't declare peanuts as an ingredient, were all negative. The detection limit of this method for purified peanut DNA was 100 pg/reaction. The sensitivity of this method was sufficient to detect peanut DNA in soybean DNA mixture which had been spiked with 0.1% peanut DNA.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.10a
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• pp.109-117
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• 2000

Bacterial community structure composing enhanced biological phosphorus removal (EBPR) activated sludge was analyzed phylogenetically by cloning 165 rDNA after direct DNA extraction. Then, this result was compared with 165 rDNA sequences of randomly isolated bacterial species. The results clearly showed that there are no coincidence between the sequences retrieved directly from activated sludge and those of isolated strains, suggesting that many important bacteria are hidden in activated sludge because of the difficulty in isolation and culture of them.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.9-16
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• 2018

The advent of available DNA barcoding technology has been extensively adopted to assist in the reference to differentiate the origin of various medicinal plants species. However, this technology is still far behind the curve of technological advances to be applied in a practical manner in the market to authenticate the counterfeit components or detect the contamination in the admixtures of medicinal plant species. Recently, a high resolution melting curve analysis technique was combined with the procedure of DNA barcoding (Bar-HRM) to accomplish this purpose. In this review, we tried to summarize the current development and bottleneck of processing related to the Bar-HRM technology for the practical application of medicinal plant species' differentiation in a viable global market. Although several successful results have been reported, there are still many obstacles to be resolved, such as limited number of DNA barcodes and single nucleotide polymorphisms, in particular, only one DNA barcode, internal transcribed sequence (ITS) of ribosomal DNA has been reported in the available nuclear genome. In addition, too few cases have been reported about the identification of counterfeit or contamination with processed medicinal plant products, in particular specifically the case of technology based infusion, jam and jelly products and components in which it is noted that DNA can be thereby degraded during the processing of these products and components.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.1-5
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• 1997

The cDNA encoding ${\beta}-tubulin$ of Pleurotus sajor-caju was isolated using an internal gene segment probe amplified by polymerase chain reaction (PCR) of genomic DNA and by cDNA library screening. The cDNA was consisted of 1560 nucleotides(nt), including a 5'-untranslation region (UTR) of 27nt, an open reading frame (ORF) of 1341nt, and a 3'-UTR of 191nt. The ORF encoded a protein of 446 amino acids(aa), which shows over 80% homology with ${\beta}-tubulins$ of other filamentous fungi. Southern hybridization analysis showed that there were two isotypes of ${\beta}-tubulin$ genes in P. sajor-caju. Through sequence analysis we found that ${\beta}-tubulin$ had a unusual $Cys^{165}$ residue, which might be a significant factor for the insensitivity of fungi to fungicide benomyl.

• Archives of Pharmacal Research
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• v.26 no.6
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• pp.493-498
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• 2003

In this study we have investigated the pharmacokinetics and tissue distribution of GX-12, a multiple plasmid DNA vaccine for the treatment of HIV-1 infection. Plasmid DNA was rapidly degraded in blood with a half-life of 1.34 min and was no longer detectable at 90 min after intravenous injection in mice. After intramuscular injection, plasmid DNA concentration in the injection site rapidly declined to less than 1 ％ of the initial concentration by 90 min post-injection. However, sub-picogram levels (per mg tissue) were occasionally detected for several days after injection. The relative proportions of the individual plasm ids of GX-12 remained relatively constant at the injection site until 90 min post-injection. The concentration of plasmid DNA in tissues other than the injection site peaked at 90 min post-injection and decreased to undetectable levels at 8 h post-injection. The rapid in vivo degradation of GX-12 and absence of persistence in non-target tissues suggest that the risk of potential gene-related toxicities by GX-12 administration, such as expression in non-target tissues, insertional mutagenesis and germline transmission, is minimal.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.22-26
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• 2002

There are a number of ways in which environmental microbiology and microbial ecology will benefit from DNA micro array technology. These include community genome arrays, SSU rDNA arrays, environmental functional gene arrays, population biology arrays, and there are clearly more different applications of microarray technology that can be applied to relevant problems in environmental microbiology. Two types of the applications, bacterial identification chip and functional gene detection chip, will be presented. For the bacterial identification chip, a new approach employing random genome fragments that eliminates the disadvantages of traditional DNA-DNA hybridization is proposed to identify and type bacteria based on genomic DNA-DNA similarity. Bacterial genomes are fragmented randomly, and representative fragments are spotted on a glass slide and then hybridized to test genomes. Resulting hybridization profiles are used in statistical procedures to identify test strains. Second, the direct binding version of microarray with a different array design and hybridization scheme is proposed to quantify target genes in environmental samples. Reference DNA was employed to normalize variations in spot size and hybridization. The approach for designing quantitative microarrays and the inferred equation from this study provide a simple and convenient way to estimate the target gene concentration from the hybridization signal ratio.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.46-51
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• 1993

The inactivating effect of iron(II)-ascorbate complex (Fe-Asc) on various phages was previously reported. This paper describes the molecular target in the phage virion attacked by Fe-Asc. The effect of Fe-Asc on protein was investigated with bovine serum albumin and the structural protein of phage J1. There were no differences in the SDS-polyacrylamide gel electrophoresis (patterns of these two proteins when either they were treated) with Fe-Asc or not. Also, there were no changes in the amino acid composition and ultraviolet spectrum of the proteins. The effects of Fe-Asc on DNA was investigated with pUC18 DNA, M13mpB DNA and ${\lambda}$ DNA as well as DNA from phage J1. Fe-Asc caused initially nicking of the subsequently form of pUC18 DNA to yield the open circular form and then subsequently the linear form. Strand breaks were also confirmed with M13mp8 DNA and ${\lambda}$ DNA as well as J1 DNA. The results indicate that the strand breaks in phage DNA could be responsible for the inactivation of phages by Fe-Asc.