• The Korean Journal of Food And Nutrition
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• v.14 no.6
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• pp.579-584
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• 2001

Chitooligosaccharides were prepared by enzymatic hydrolyzing of crab shell chitosan. Low Molecular Meight chitooligosaccharides(LMW-chitooligosaccharides) , 64.3% of which was composed of trimer, tetramer, and pentamer, was obtained by hydrolyzing chitosan with the chitosanase originated Bacillus pumilus BN -262. High Molecular Meight chitooligosaccharides ( HMW-chitooligosaccharides ) , 49.3% of which was composed of chitooligosaccharides over heptamer, was obtained by hydrolyzing chitosan with the cellulase originated Trichoderma viride. Antimicrobial activity and colony forming inhibitory activity of chitooligosaccharides were tested. MIC of LMW-chitooligosaccharides against Bacillus cereus, Bacillus subtilis, Candida albicans, Escherichia coli, Escherichia coli O157 : H7, Lactobacillus plantarum, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus and Streptococcus mutans was 1.5%, 1.5% above 2.0%, 1.5%, 1.5%, below 0.5%, 2.0%, 1.5%, above 2.0%, 1.0%, 1.5% and 1.0% respectively. .

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.171-178
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• 2017

This study evaluated the protective effect of Chungkookjang (CKJ) extract, a Korean traditional fermented soybean product made from Bacillus species in rice straw and boiled soybean, and one of its main flavonoids, genistein, against Trp-P-1 induced cytotoxicity and DNA damage in HepG2 cells. CKJ and genistein exhibited protective effect against Trp-P-1 induced cytotoxicity and Trp-P-1 induced DNA single strand breaks. CKJ and genistein inhibited Trp-P-1 induced CYP1A1 and CYP1A2 transcription in HepG2 cells. Our results indicated that CKJ and genistein have the protective effect against Trp-P-1 induced cytotoxicity and DNA damage. Via inhibiting expression of CYP1A1 and CYP1A2. CKJ can be used as a promising functional food material that prevents the genotoxicity induced by carcinogens produced by the heat treatment of foods such as heterocyclic amines (HCAs) that cause genomic instability.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.1977-1988
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• 2015

β-1,3-glucanosyltransferases play essential roles in cell wall biosynthesis in yeast. Kluyveromyces lactis has six putative β-1,3-glucanosyltransferase genes. KlGAS1-1 and KlGAS1-2 are homologs of Saccharomyces cerevisiae gene GAS1. RT-qPCR indicated the transcription level of KlGAS1-1 was significantly reduced while heterologous protein (thermostable xylanase B) secretion was enhanced during medium optimization. To evaluate if these two events were related, and to improve xylanase B secretion in K. lactis, we constructed KlGAS1-1 and KlGAS1-2 single deletion strains and double deletion strain, respectively. KlGAS1-1 gene deletion resulted in the highest xylanase B activity among the three mutants. Only the double deletion strain showed morphology similar to that of the GAS1 deletion mutant in S. cerevisiae. The two single deletion strains differed in terms of cell wall thickness and xylanase B secretion. Transcription levels of β-1,3-glucanosyltransferase genes and genes related to protein secretion and transport were assayed. The β-1,3-glucanosyltransferase genes displayed transcription complementation in the cell wall synthesis process. KlGAS1-1 and KlGAS1-2 affected transcription levels of secretion- and transport-related genes. Differences in protein secretion ratio among the three deletion strains were associated with changes of transcription levels of secretion- and transport-related genes. Our findings indicate that KlGAS1-1 deletion is an effective tool for enhancing industrial-scale heterologous protein secretion in K. lactis.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.171-174
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• 2012

THOC1/Hpr1 is one subunit of THO complex that is an evolutionally conserved assembly involved in the mRNP packaging and mRNA export during transcription elongation. In fission yeast Schizosaccharomyces pombe, an ortholog (spHpr1) of THOC1/Hpr1 was identified based on sequence alignment. A deletion mutant in a diploid strain was constructed by replacing one of spHpr1-coding region with a $kan^r$ gene using one-step gene disruption method. Tetrad analysis showed that the sphpr1 is essential for growth. Over-expression of sphpr1 from strong nmt1 promoter caused no defects of growth and mRNA export. However, repression of the sphpr1 expression resulted in growth inhibition accompanied by accumulation of poly$(A)^+$ RNA in the nucleus. These results suggest that spHpr1 is involved in mRNA export from the nucleus to cytoplasm.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.33-36
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• 2001

The experiments were conducted to establish the in vitro culture system of apple rootstock M.9. The meristem tissue of M.9 were pre-treated in antiox: dant solution containing 100 mgL$^{-1}$ ascorbic acid and 150 mgL$^{-1}$ citric acid for 30 minutes, transferred to the MS liquid medium added with 0.1 mgL$^{-1}$ IBA, 0.5 mgL$^{-1}$ GA, and 30 gL$^{-1}$ sucrose, which shaked by 50 rpm for 2 weeks, and then, cultured in same composition of MS agar medium. This treatment stimulated shooting from the tissue, the most favorably, compared with other treatments. All young shoots produced normal roots when they were shake-cultured on the 1/2MS liquid medium added with 0.5 mgL$^{-1}$ IBA, 30 gL$^{-1}$ sucrose and 1,000 times diluted solution of Hormex by 50 rpm for one week, and subsequently transferred to the 8 gL$^{-1}$ agar medium of the same composition as pre-culture medium minus Hormex.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1639-1644
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• 2012

The aim of this study was to investigate the expression and significance of microsomal prostaglandin synthase-1 (mPGES-1) and Beclin-1 in the development of prostate cancer (PCa). Immunohistochemistry was performed on paraffin-embedded sections with rabbit polyclonal against mPGES-1 and Beclin-1 in 40 PCa, 40 benign prostatic hyperplasia (BPH) and 10 normal prostate specimens for this purpose. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for mRNA expression of mPGES-1 and Beclin-1, while MTT assays were used to ascertain the best working concentration of the mPGES-1 inhibitor (CAY10526). The effect of CAY10526 treatment on expression of Beclin-1 in DU-145 cells was studied using Western blot analysis. Localization of Beclin-1 and mPGES-1 was in endochylema. Significant differences in expression was noted among PCa, BPH and normal issues (P<0.05). Beclin-1 expression inversely correlated with mPGES-1 expression in PCa tissue (P<0.05). CAY10526 could significantly block mPGES-1 expression and the proliferation of DU-145 cells (P<0.05), while increasing Beclin-1 levels (P<0.05). Overexpression of mPGES-1 could decrease the autophagic PCa cell death. Inhibiting the expression of mPGES-1 may lead to DU-145 cell death and up-regulation of Beclin-1. The results suggest that inhibition of mPGES-1 may have therapeutic potential for PCa in the future.

• Journal of the Korean Magnetics Society
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• v.26 no.3
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• pp.71-75
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• 2016

Monolayer $MoS_2$ is energetically most stable when it has a 1H phase, but 1H to 1T phase transition ($1H{\rightarrow}1T$) is easily realized by various ways. Even though magnetic moment is not observed during $1H{\rightarrow}1T$, $0.049{\mu}_B/MoS_2$ is obtained in local 1T phase; 75% 2H and 25% 1T phases are mixed in ($2{\times}2$) supercell. Most magnetic moment is originated from the 1T phase Mo atom in the supercell, while the magnetic moments of other atoms are negligible. As a result, magnetic/non-magnetic boundary is created in the monolayered $MoS_2$. Our result suggests that $MoS_2$ can be applied for spintronics such as a spin transistor.

• Archives of Pharmacal Research
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• v.21 no.2
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• pp.198-206
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• 1998

Fourty eight derivatives of 2-(1-oxyalkyl)-1,4-dioxy-9,10-anthraquinone were synthesized, and their antitumor activity was evaluated. On the whole, 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinones (DHAQ=1,4-dihydroxy-9,10-anthraquinone) showed stronger cytotoxic activity against L1210 cells than 2-(l-hydroxyalkyl)-1,4-dimethoxy-9,10-anthraquinones(DMAQ =1,4-dimethoxy-9,10-anthraquinone), implying that free hydroxy groups at C-1 and C-4 of the anthraquinone structure are necessary for the cytotoxic activity. The bioactivity of 2-(lhydroxyalkyl)-DHAQ derivatives differed according to the size of alkyl group at C-1;while the elongation of alkyl group over 7 carbon atoms failed to enhance the bioactivity, the derivatives possessing alkyl moiety of 1-6 carbon atoms showed an increase in the cytotoxicity and the antitumor activity in Sarcoma-180; 2-hydroxymethyl-DHAQ ($ED_{50}$, $15\mu\textrm{g}$/ml; T/C, 125%), 2-(1 -hydroxyethyl)-DHAQ($1.9{\mu}g/ml;139.2%)$;, 2-(1-hydroxypropyl)-DHAQ ($7.2{\mu}g$/ml; 135.1%), 2-(1-hydroxybutyl)-DHAQ ($10.2{\mu}g/ml; 125.3%)$, 2-(1-hydroxypentyl)-DHAQ ($23.7{\mu}g/ml; 110.1%$). and 2-(1-hydroxyhexyl)-DHAQ ($58{\mu}g/ml;108%$). Next, 2-(1-Hydroxyalkyl)-DHAQ derivatives were acetylated to produce 2-(1-acetoxyalkyl)-DHAQ analogues. Although the acetylation somewhat enhanced the cytotoxicity, but not the antitumor action. In addition, the presence of phenyl group at $C-1^{l}$ enhanced the cytotoxicity and the T/C value, compared to alkyl groups of same size; 2-(1-hydroxy-1-phenyl)-DHAQ ($ED_{50}$, $5.6{\mu}g$, T/C, 137%).

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.9-21
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• 2005

To study the biochemical and physiological role of the plastidic glucose transporter (pGlcT) in carbohydrate metabolism, we characterized transgenic plants with mutations in the pGlcT gene (GT), gt-1 and gt-2, as well double mutants of GT and the maltose transporter (MEX1) and GT and the triose phosphate/phosphate translocator (TPT), GT and the cytosolic fructose-1,6-bisphosphatase gene (cFBP), and MEX1 and TPT, gt-1/mex2, gt-1/tpt-2, gt-1/cfbp-1, mex1-1/tpt-2, respectively. Compared to the wild type, all mutants except the gt-1/cfbp-1 mutant lines displayed higher starch accumulation and higher levels of maltose. Starch accumulation is due to a decrease in starch turnover, leading to an imbalance between the rates of synthesis and degradation. Sucrose levels of gt alleles were higher than those in wild-type plants during the light period, suggesting possible nightly supplementation via the maltose transport pathway to maintain proper carbohydrate partitioning in the plant leaves. The gt plants displayed less growth retardation than mex1-1 mutant and gt-1/mex2 double mutant displayed accumulativesevere growth retardation as compared to individual gt-1 and mex1-1 mutants, implying that the maltose transporter-mediated pathway is a major route for carbohydrate partitioning at night. The gt-1/tpt-2, mex1-1/tpt-2 and gt-1/cfbp-1 double mutants had retarded growth and low chlorophyll content to differing degrees, indicating that photosynthetic capacity had diminished. Interestingly, the gt-1/tpt-2 line displayed a glucose-insensitive phenotype and higher germination rates than wild type, suggesting its involvement not only in carbon partitioning, but also in the sugar signaling network of the pGlcT and TPT.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3325-3328
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• 2012

Aim: To evaluate the association of glutathione S-transferases gene polymorphisms with the risk of gastric cancer, with reference to smoking and Helicobacter pylori infection. Methods: We conducted a 1:1 matched case-control study with 410 gastric cancer cases and 410 cancer-free controls. Polymorphisms of GSTM1, GSTT1 and GSTP1 were determined using PCR-CTPP. Results: The GSTM1 and GSTT1 null genotypes were significantly associated with the risk of gastric cancer after adjusting for potential confounding factors (OR=1.68, 95% CI=1.32-2.23 for null GSTM1, OR=1.73; 95% CI=1.24-2.13 for null GSTT1). The combination of null GSTM1 and null GSTT1 conferred an elevated risk (OR=2.54, 95% CI=1.55-3.39). However, no association was found for GSTP1 polymorphism The smoking modified the association of GSTM1 and GSTT1 null genotypes with the risk of gastric cancer. Conclusion: GSTM1 and GSTT1 null genotypes are associated with increased risk of gastric cancer, and smoking modifies the association.