• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.299-308
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• 2007

Insoluble glucan is the important component of oral biofilm, which is synthesized from sucrose through the action of glucosyltransferase (GTF) B and GTF C encoded by the gtfB and gtfC genes, respectively of Streptococcus mutans. In present study, the effects of various sugars on the mRNA expression of gtfB and gtfC of S. mutans Ingbritt were examined by fluorescent in situ hybridization (FISH). The mRNA of gtfB and gtfC was expressed normally in the BHI broth containing 1% and 5% sucrose. The mRNA expression was decreased by the addition of 10% of glucose, and 1%, 5% and 10% of fructose. Lactose had no great effect on the expression of gtfB and gtfC. 5% and 10% of xylitol greatly reduced the mRNA expression of gtfB and gtfC. Sorbitol slightly decreased the mRNA expression of gtfB and gtfC when compared to the control. In summary, mRNA expression of gtfB and gtfC was decreased by the addition of glucose, fructose, and xylitol.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.357-369
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• 2005

Streptococci are Gram-positive, facultative anaerobes and have no catalase activities. Among mutans streptococci containing ${\alpha}-type$ hemolytic activity, S. mutans is a causative agent for dental caries. As well as acid production yielding the demineralization of tooth enamel, adherence and colonization of S. mutans to the teeth are also important for its virulence. These early colonization are accomplished by the bacterial fibrillar protein, Antigen I/II (Ag I/II) and glucosyltransferase (GTF). Therefore, Ag I/II and GTF are reasonable targets for the development of vaccine against S. mutans GS-5. The ag I/II and gtfD genes from S. mutans GS-5 were cloned and sequenced. Sequence analyses showed the nucleotides sequence of cloned genes had high homology to the sequences previously reported. The sequence alignment of 280 nucleotides between the cloned Ag I/II and the available sequence of the corresponding S. mutans GS-5 showed the perfect match. Comparing with the sequence of gtfD from S. mutans UA159, the corresponding nucleotide sequence of S. mutans GS-5 showed some mismatches and the mismatches introduced changes in four residues out of 105 amino acids, yielding four missense mutations.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.84-87
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• 2008

In this research, we screened for glucosyltransferase (GTase) inhibitors that effectively prevent the dental caries from 420 kinds of boiled water extracts of herbs and wild plants and searched for GTase inhibitory activities. Among them, 13 kinds of hot water extracts had high GTase inhibitory activities and especially, we focused on Foeniculum vulgare which showed the highest inhibitory activity on GTase. The boiled water extract of F. vulgare was stable at high temperature and showed as a mixed type of competitive and uncompetitive inhibition kinetic behavior. It did not have antibacterial effect on Streptococcus mutans and had inhibitory activity on GTase. Specially, in the clinical trial, the group treated by boiled water extract of F. vulgare showed more decrease of plague index at 4.8 point than untreated group. These results suggested that boiled water extract of F. vulgare can effectively suppress the plague formation as it inhibits the GTase activity.

• Journal of Life Science
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• v.31 no.1
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• pp.100-108
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• 2021

In the oral cavity, there are hundreds of microbial species that exist as planktonic cells or are incorporated into biofilms. The accumulation and proliferation of pathogenic bacteria in the oral biofilm can lead to caries and periodontitis, which are typical oral diseases. The oral bacteria in the biofilm not only can resist environmental stress inside the oral cavity, but also have a 1,000 times higher resistance to antibiotics than planktonic cells by genes exchange through the interaction between cells in the oral biofilm. Therefore, if the formation of oral biofilm is suppressed or removed, oral diseases caused by bacterial infection can be more effectively prevented or treated. In particular, since oral biofilms have the characteristic of forming a biofilm by gathering several bacteria, quorum sensing, a signaling system between cells, can be a target for controlling the oral biofilm. In addition, a method of inhibiting biofilm formation by using arginine, an alkali-producing substrate of oral bacteria, is used to convert the distribution of oral microorganisms into an environment similar to that of healthy teeth or inhibit the secretion of glucosyltransferase by S. mutans to inhibit the formation of non-soluble glucans. It can be a target to control oral biofilm. This method of inhibiting or removing the oral biofilm formation rather than inducing the death of pathogenic bacteria in the oral cavity will be a new strategy that can selectively prevent or therapeutic avenues for oral diseases including dental caries.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.1
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• pp.37-41
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• 2001

The ecdysteroid UDP-glucosyltransferase (egt) gene isolated from Bombyx mori nuclear polyhedrosis virus (BmNPV) K1 strain was compared to its homologue from Autographa californica NPV (AcNPV) and Bm NPV T3. The egt gene of BmNPV-K1 encoded 506 amino acid open reading frame, and was 99.6% identical at the amino acid level and 99.2% identical at the nucleotide level to BmNPV T3. The BmNPV-K1 egt gene showed highly identity to AcNPV and BmNPV T3 strain. The BmNPV-K1 egt gene was different from amino acid sequence at 2 positions, 19 and 72, in BmNPV T3. The genomic location of egt gene in the BmNPV-K1 was confirmed by Southern blot analysis and its expression patterns at the transcriptional level in the infected cells were confirmed by Northern hybridization analysis. Transcripts of the egt of Bm NPV-K1 peaked around 12 hrs postinfection (p.i.) and reduced at 24 hrs p.i.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.1083-1086
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• 2010

This study was conducted to investigate the inhibitory effects of daidzein against H. pylori and its cholesterol $\alpha$-glucosyltransferase ($CHL{\alpha}GcT$). $CHL{\alpha}GcT$ is responsible for the production of $\alpha$-glucosyl cholesterol which constitutes more than 25% of cell wall lipids in H. pylori, and it has been suggested that it is essential for H. pylori viability. $CHL{\alpha}GcT$ was inhibited by daidzein, in a dose-dependant manner, of which $IC_{50}$ value was $128.5\;{\mu}M$. Daidzein also showed the inhibitory effect toward H. pylori growth by paper disc diffusion assay. Therefore, it is thought that the inhibition of daidzein on $CHL{\alpha}GcT$ was related to its anti-Helicobacter activity.

• Journal of Plant Biotechnology
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• v.46 no.4
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• pp.247-254
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• 2019

Flavonoids are widely distributed secondary metabolites in plants that have a variety biological functions, as well as beneficial biological and pharmacological activities. In barley (Hordeum vulgare L.), for example, high levels of saponarin accumulate during primary leaf development. However, the effect of saponarin biosynthetic pathway genes on the accumulation of saponarin in barley is poorly understood. Accordingly, the aim of the present study was to examine the saponarin contents and expression levels of saponarin biosynthetic pathway genes [chalcone synthase (CHS), chalcone isomerase (CHI), and UDP-Glc:isovitexin 7-O-glucosyltransferase (OGT)] during early seedling developmental and under several abiotic stress conditions. Interestingly, the upregulation of HvCHS, HvCHI, and HvOGT during early development was associated with saponarin accumulation during later stages. In addition, exposure to abiotic stress conditions (e.g., light/dark transition, drought, and low or high temperature) significantly affected the expression of HvCHS and HvCHI but failed to affect either HvOGT expression or saponarin accumulation. These findings suggested that the expression of HvOGT, which encodes an enzyme that catalyzes the final step of saponarin biosynthesis, is required for saponarin accumulation. Taken together, the results of the present study provide a basis for metabolic engineering in barley plants, especially in regards to enhancing the contents of useful secondary metabolites, such as saponarin.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.304-313
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• 2004

Xylitol, a five-carbon natural sugar alcohol, is widely used non-cariogenic sugar substitute. In present study, the effects of xylitol on the expression of mRNA for glucosyltransferase which synthesizes glucan from sucrose were detected by Fluorescent in situ hybridization (FISH) and flow cytometry. FITC fluorescences for mRNA of gtfB, gtfC and gtfD were decreased further with increasing concentration of xylitol from 1% to 10% when detected by FISH. Flow cytometric analysis also showed that the expression of gtfB, gtfC and gtfD was increased by the addition of sucrose and decreased by the addition of xylitol to BHI broth containing 1% sucrose. In conclusion, the expression of gtfB, gtfC and gtfD mRNA was decreased by the addition of xylitol.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.12-17
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• 2021

Saponarin found in young barley sprouts has a variety of beneficial biological and pharmacological properties, including antioxidant, hypoglycemic, antimicrobial, and hepatoprotective activities. Our previous work demonstrated that saponarin content was correlated with the expression levels of three biosynthetic pathway genes [chalcone synthase (HvCHS1), chalcone isomerase (HvCHI), and UDP-Glc:isovitexin 7-O-glucosyltransferase (HvOGT1)] in young barley seedlings under various abiotic stress conditions. In this study, we investigated the saponarin content and expression levels of three saponarin biosynthetic pathway genes in hulled and hulless domestic barley cultivars. In the early developmental stages, some hulled barley cultivars (Kunalbori1 and Heukdahyang) had much higher saponarin contents than did the hulless barley cultivars. An RNA expression analysis showed that in most barley cultivars, decreased saponarin content correlated with reduced expression of HvCHS1 and HvCHI, but not HvOGT1. Heat map analysis revealed both specific increases in HvCHS1 expression in certain hulled and hulless barley cultivars, as well as general changes that occurred during the different developmental stages of each barley cultivar. In summary, our results provide a molecular genetic basis for the metabolic engineering of barley plants to enhance their saponarin content.

• Korean Journal of Microbiology
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• v.19 no.3
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• pp.137-141
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• 1981

Occurrence and distribution of sucrose metabolizing enzymes in oral streptococci had been studied. In these studies, the carbohydrate component of the culture medium had been glucose. I have extended these studies by analyzing bacterial culture supernatants for the relative content of hexosyltransferases, namely glucosyl and fructosyltransferase. As a carbohydrate, fructose was used. The growth measured for nine oral streptococci (Strptococcus mutans strains BHT, ING, AHT, 6715, LM-7, and SL-1 ; Streptococcus sanguis 903, 9811, and M-5) varied. The level of glucosyltansferase activity also varied among S. mutans strains, and its level in S. sanguis was relatively low. Fructosyltansferase activity of the various strains fluctuated more than of glucosyltransferase. S.mutans strain LM-7 had significantly higher level of both enzymes. As a whole, fructose-grown cultures had generally an agreeable trend of enzyme activity to those from glucose-grown cultures.