• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.971-975
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• 2008

Human cytomegalovirus (HCMV) provokes fatal infections in AIDS patients that have deficient immune functions and patients that have cellular immune responses repressed after bone marrow transplantation. A new candidate for therapeutic against HCMV is needed because conventional treatments as ganciclovir, acyclovir, cidofovir, and foscarnet cytosine used currently are improper due to their side effects and advent of resistant HCMV. In this study, peptide nucleic acids (PNAs) against UL54 (DNA polymerase) and UL97 (phosphotransferase) that were essential in replication of HCMV were applied in inhibition of replication of HCMV. From the results of this study, 4 PNAs $_{PNA}UL97-1$, $_{PNA}UL97-2$, $_{PNA}UL54-3$, and $_{PNA}UL54-4$ showed 3.7, 3.1, 1.7, and 1.6 folds of inhibition effect against replication of HCMV in the human fibroblast cells. These PNA suggest a novel possibility as therapeutic against HCMV.

• Journal of Ginseng Research
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• v.27 no.1
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• pp.17-23
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• 2003

Agrobacterium-mediated transformation of American ginseng (Panax quinquefolius L.) with strain LBA 4404 containing a rice thaumatin-like protein gene is described. The selectable markers used were phosphinothricin acetyltransferase and hygromycin phosphotransferase genes. Epicotyl explants from seedlings were precultured for 5-7 days on Murashige and Skoog medium with ${\alpha}$-naphthaleneacetic acid and 2,4 dichlorophenoxyacetic acid at 10 ${\mu}$M and 9 ${\mu}$M, respectively (ND medium), prior to Agrobacterium infection. The explants were immersed in a bacterial suspension for 20 min. A post-infection co-culture period of 3-4 days was provided on ND medium. Selection for transformed calli was conducted on ND medium with 20 mg/L phosphinothricin followed by 100 mg/L hygromycin over an 8-month period. it transformation frequency of 24.8% was achieved at the callusing phase. The presence of the transgenes in calli was confirmed by Southern hybridization and polymerase chain reaction analysis. The expression of the thaumatin-like protein gene in ginseng calli was demonstrated by Western blot analysis. Somatic embryos were produced from both transgenic calli and suspension cultures, and plantlets were recovered that expressed the transgenic thaumatin-like protein gene.

• International Journal of Oral Biology
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• v.38 no.4
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• pp.175-180
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• 2013

Xylitol is a five-carbon sugar alcohol that reduces the incidence of caries by inhibiting the growth of oral streptococci, including Streptococcus mutans. Since xylitol is transported via the fructose phosphotransferase system, we hypothesized that it could also affect the growth of other oral bacteria strains. We tested the effects of xylitol against non-periodontopathogenic oral bacteria frequently found in healthy subjects as well as periodontopathogens including Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. With 5% xylitol, Streptococcus vestibularis and Gemella morbillorum showed marked growth inhibition. With 10% xylitol, all of the tested periodontopathogens and Actinomyces naeslundii showed marked growth inhibition, whereas the growth inhibition of Neisseria mucosa, Neisseria sicca and Veillonella parvula was mild only. Xylitol is a widely used sweetener and the concentration used in our experiment is easily achieved in the oral cavity. If xylitol reduces the growth of periodontopathogens more preferentially, it could also reduce the prevalence of these pathogens and have clinical utility in the prevention or treatment of periodontal disease.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.129-138
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• 2010

An efficient transformation system for high-throughput functional genomic studies of kiwifruit has been developed to overcome the problem of necrosis in Actinidia arguta explants. The system uses Agrobacterium tumefaciens strain EHA105 harbouring the binary vector pART27-10 to inoculate leaf strips. The vector contains neomycin phosphotransferase (nptII) and ${\beta}$-glucuronidase (GUS) (uidA) genes. A range of light intensities and different strengths of Murashige and Skoog (MS) basal salt media was used to overcome the problem of browning and/or necrosis of explants and calli. Callus browning was significantly reduced, resulting in regenerated adventitious shoots when the MS basal salt concentration in the culture medium was reduced to half-strength at low light intensity ($3.4\;{\mu}mol\;m^{-2}\;s^{-1}$) conditions. Inoculated leaf strips produced putative transformed shoots of Actinidia arguta on half-MS basal salt medium supplemented with 3.0 $mg\;l^{-1}$ zeatin, 0.5 $mg\;l^{-1}$ 6-benzyladenine, 0.05 $mg\;l^{-1}$ naphthalene acetic acid, 150 $mg\;l^{-1}$ kanamycin and 300 $mg\;l^{-1}$ $Timentin^{(R)}$. All regenerated plantlets were deemed putativ transgenic by histochemical GUS assay and polymerase chain-reaction analysis.

• BMB Reports
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• v.30 no.2
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• pp.125-131
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• 1997

This work reports studies of the catalytic and structural properties of pyridoxal kinase (ATP: pyridoxal 5' -phosphotransferase, EC. 2.7.1.35), Pyridoxal kinase catalyzes the phosphorylation of vitamin $B_6$ (pyridoxal, pyridoxamine, pyridoxine) using ATP-Zn as a phosphoryl donor. The enzyme purified from brain tissues is made up of two identical subunits of 40 kDa each. Native enzyme was inhibited by a substrate analogue, pyridoxal-oxime. Limited chymotrypsin digestion of pyridoxal kinase yields two fragments of 24 and 16 kDa with concomitant loss of catalytic activity. These fragments were isolated by DEAE ion exchange chromatography and used for binding studies with fluorescent ATP and pyridoxal analogues. The spectroscopic properties of both fluorescent pyridoxal analogue and Anthraniloyl ATP (Ant-ATP) bound to the 24 kDa fragment are indistinguishable from those of both pyridoxal analogue and Ant-ATP bound to the native pyridoxal kinase, respectively. The small 16 kDa fragment, generated by proteolytic cleavage of the kinase, does not bind any of the substrate analogues. Binding characteristics of Ant-ATP were extensively studied by measuring the changes in fluorescence spectra at various conditions. From the results presented herein, it is postulated that the structural domain associated with catalytic activity comprises approximately one-half of the molecular mass of pyridoxal kinase (24 kDa). whereas the remaining portion (16 kDa) of the enzyme contains a regulatory binding domain.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.454-464
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• 2018

Salivary microbiota alterations can correlate with dental caries development in children, and mechanisms mediating this association need to be studied in further detail. Our study explored salivary microbiota shifts in children and their association with the incidence of dental caries with dentine involvement. Salivary samples were collected from children with caries and their subsequently matched caries-free controls before and after caries development. The microbiota was analyzed by 16S rRNA gene-based high-throughput sequencing. The salivary microbiota was more diverse in caries-free subjects than in those with dental caries with dentine involvement (DC). Although both groups exhibited similar shifts in microbiota composition, an association with caries was found by function prediction. Analysis of potential microbiome functions revealed that Granulicatella, Streptococcus, Bulleidia, and Staphylococcus in the DC group could be associated with the bacterial invasion of epithelial cells, phosphotransferase system, and ${\text\tiny{D}}-alanine$ metabolism, whereas Neisseria, Lautropia, and Leptotrichia in caries-free subjects could be associated with bacterial motility protein genes, linoleic acid metabolism, and flavonoid biosynthesis, suggesting that functional differences in the salivary microbiota may be associated with caries formation. These results expand the current understanding of the functional significance of the salivary microbiome in caries development, and may facilitate the identification of novel biomarkers and treatment targets.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1528-1531
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• 2015

Sclerotia of Wolfiporia cocos are of medicinal and culinary value. The genes and molecular mechanisms involved in W. cocos sclerotial formation are poorly investigated because of the lack of a suitable and reproducible transformation system for W. cocos. In this study, a PEG/CaCl₂-mediated genetic transformation system for W. cocos was developed. The promoter P_gpd from Ganoderma lucidum effectively drove expression of the hygromycin B phosphotransferase gene in W. cocos, and approximately 30 transformants were obtained per 10 μg DNA when the protoplast suspension density was 10⁶ protoplasts/ml. However, no transformants were obtained under the regulation of the PtrpC promoter from Aspergillus nidulans.

• Journal of Nutrition and Health
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• v.35 no.1
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• pp.53-59
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• 2002

Green tea has been recognized as a favorite beverage for centuries in Easter and Westers cultures. Recently, anti-tumor effects of green tea constituents have received increasing attention. However, the mechanism of catechin-mediated cytotoxicity against tumor cells remains to be elusive. To elucidate the mechanical insights of anti-tumor effects, (-)epigallocatechin-gallate(EGCG) of catechin was applied to human lung cancer A549 cells. (-)EGCG induced the death of A549 cells, which was revealed as apoptosis in DNA fragmentation assay. (-)EGCG induced the activation of caspase family cysteine proteases including capase-3, -8 and -9 proteases in A549 cells. Furthermore, (-)EGCG increased the phosphotransferase activity of c-Jun N-terminal kinase 1JNK 1), which further induced tole transcriptional activation of activating protein-1(AP-1) in A549 cells. We suggest that (-)EGCG-induced apotosis of A549 cells is mediated by signaling pathway involving caspase family cysteine protease, JNK1 and transcription factor, AP-1.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.795-798
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• 2006

The phosphoenolpyruvate-dependent carbohydrate phosphotransferase system (PTS) is responsible for the simultaneous transfer and phosphorylation of various carbon sources in Escherichia coli. The ptsG gene encoding the enzyme $IICB^{Glc}$, the membrane component of the glucose-specific PTS, is repressed by Mlc and activated by the CRP cAMP complex; various other factors, such as Fis, FruR, and ArcA, are also known to be involved in ptsG regulation. Thus, in an attempt to discover a novel gene affecting the regulation of ptsG, a mutant with a decreased ptsG transcription in the presence of glucose compared with the wild-type strain was screened using transposon random mutagenesis. The mutant was found to have a transposon insertion in yhjV, a putative gene encoding a transporter protein whose function is yet unknown.

• Mycobiology
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• v.38 no.4
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• pp.331-335
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• 2010

In this study, we developed an efficient electroporation-mediated transformation system featuring Flammulina velutipes. The flammutoxin (ftx) gene of F. velutipes was isolated by reverse transcription-PCR. pFTXHg plasmid was constructed using the partial ftx gene (410 bp) along with the hygromycin B phosphotransferase gene (hygB) downstream of the glyceraldehydes-3-phosphate dehydrogenase (gpd) promoter. The plasmid was transformed into protoplasts of monokaryotic strain 4019-20 of F. velutipes by electroporation. High transformation efficiency was obtained with an electric-pulse of 1.25 kV/cm by using 177 transformants/${\mu}g$ of DNA in $1{\times}10^7$ protoplasts. PCR and Southern blot hybridization indicated that a single copy of the plasmid DNA was inserted at different locations in the F. velutipes genome by non-homologous recombination. Therefore, this transformation system could be used as a useful tool for gene function analysis of F. velutipes.