• Food Science and Preservation
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• v.18 no.2
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• pp.184-190
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• 2011

Limonoid UDP-glucosyltransferase (LUGT) is an enzyme that converts limonoids into their corresponding glucosides and ultimately ameliorates limonoid bitterness in Citrus species. In this paper, the LUGT gene was cloned via PCR from 10 Jeju Citrus species. All the deduced glucosyltransferase proteins harbored a highly conserved plant secondary product glucosyltransferase (PSPG) motif within the C terminal region. Phylogenetic analysis based on the amino acid sequence comparison of the LUGT proteins from 10 Citrus species generated three distinct types. The expression patterns of LUGT gene in three representative species from each type were quite different with that of C. unshiu Marc. cv. Miyagawawase(Gungcheon), which his without distinctive juice delayed bitterness. Ourresultssho wth at some Citrus speciessuchas Citrusleiocarpa HORT(Bingul), Citruserythrosa HORT (Dongjunggul), and Citrustachibana TANAKA(Honggul) end emicin Jeju maybe susceptible to intense juice delayed bitterness due to delay inexpression of LUGT.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.105-110
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• 1998

The baculovirus egt gene encodes an ecdysteroid UDP-glucosyltransferase(EGT) which catalyzes the transfer of glucose from UDP-glucose to the insect moltion hormone ecdysteroid resulting in a functionally inactive ecdysteroid. In baculovirus-infected insect larvae, EGT has been shown block molting and pupation. In this study, we compared the development of 4th and 5th instar silkworm, Bombyx mori, larvae injected with either wild-type bombyx mori nucleopolyhedrovirus (BmNPV) or a mutant BmNPV(BmEGTZ) in which the egt gene was disrupted by the insertion of a lacZ gene cassette. Larvae injected with BmEGTZ died roughly 12 h more rapidly compared to indentical larvae infected with BmNPV. In addition, BmEGTZ- infected larvae prematurely stopped feeding and gain less weight compared to BmNPV-infected larvae. In order to investigate why BmEGTZ-infected larvae died more rapidly than BmNPV-infected larvae, the array of hemolymph proteins in BmEGTZ-or BmNPV-infected larvae were analyzed by SDS-PAGE. The hemolymph of BmEGTZ-infected larvae showed virus-specific proteins, including polyhedrin, about 12 h earlier than the hemolymph of BmNPV-infected larvae

• YAKHAK HOEJI
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• v.49 no.2
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• pp.122-127
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• 2005

Dental caries is one of the most common oral diseases in the world. Glucosyltransferase (Gtase) of Streptococcus mutans (S. mutans) plays an important role in the develo pment of dental caries. For the purpose to develop anti- caries, we examined the effect of metabolites isolated from Streptomyces sp. M-20 on Gtase and the growth of S. mutans. Streptomyces sp. M-20 isolated from Mongolian soil showed 95~96% sequence homology with that of Streptomyces lin- colnensis. The metabolites of Streptomyces sp. M-20 were partially purified by extraction with ethyl acetate, silica gel column chromatography and preparative TLC. Partially purified metabolite, red colored component (MR-20) in ethyl acetate fraction showed potent antibacterial activitiy against S. mutans and inhibitory activity against Gtase purified from S. mutans, while another isolated yellow component (MY-20) showed no activity against S. mutans. The inhibitory activity of MR-20 against Gtase was confirmed by activity staining on SDS-polyacrylamide gel electrophoresis. The concentration of MR-20 for 50% inhibition $(IC_{50})$ against Gtase activity was $60{\mu}g/ml$. These results suggest that MR-20 can be developed for antibacterial agent and anticaries.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.77-84
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• 2006

Since the long-term exposure of mutans streptococci to xylitol is known to select for xylitol-resistant $(X^R)$ natural mutants, the occurrence and survival of such $(X^R)$ strains were performed in batch culture methods. The aim of the study was to compare the differentiation and quantification of mRNA expression of the gtf genes of $X^R\;and\;X^S$ mutans streptococci. Using a real-time reverse-transcription polymerase chain reaction, the expression of each gtf was determined. In $X^R$ strains, the relative levels of transcription of gtfB and gtfC were decreased while that of gtfD was increased, suggesting the presence of independent promoters. It also suggested that mutation related to production of glucosyltransferase occurred under the exposure of xylitol could explain the caries-preventive mechanisms of xylitol.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1542-1546
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• 2009

Zeaxanthin glucosyltransferase (CrtX) mediates the formation of zeaxanthin to zeaxanthin diglucoside. Here, we report cloning of the crtX gene responsible for zeaxanthin diglucoside biosynthesis from Paracoccus haeundaensis and the production of the corresponding carotenoids in transformed cells carrying this gene. An expression plasmid containing the crtX gene (pSTCRT-X) was constructed, and Escherichia coli cells containing this plasmid produced the recombinant protein of approximately 46 kDa. Biosynthesis of zeaxanthin diglucoside was obtained when the plasmid pSTCRT-X was co-transformed into E. coli containing the pET-44a(+)-CrtEBIYZ carrying crtE, crtB, crtI, crtY, and crtZ genes required for zeaxanthin $\beta$-D-diglucoside biosynthesis.

• Current Research on Agriculture and Life Sciences
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• v.31 no.2
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• pp.83-87
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• 2013

AtSAGT1 encodes a salicylic acid (SA) glucosyltransferase enzyme that catalyzes the formation of SA glucoside and SA glucose ester. Here, the AtSAGT1 gene expression patterns were determined in AtSAGT1 promoter::GUS transgenic Arabidopsis plants. As a result, the factors regulating the induction of AtSAGT1 were identified as pathogen defense response, wound response, exogenous application of SA, and jasmonic acid treatment.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1221-1223
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• 2010

본 논문에서는 한국인 아동의 우식치아로부터 S. mutans를 분리하고, acid stress하에서 분리한 S. mutans의 유전자의 발현의 변화를 분석하고자 하였다. 치아우식증의 주요한 요소로 작용하는 치태형성에 기여하는 glucan 및 fructan 합성에 관여하는 세포내 효소인 glucosyltransferase, glucosyltransferase, glucosyltransferase 및 fructosyltransferase의 발현량의 변화를 확인한 결과, lactic acid를 처리하지 않은 control의 경우보다 16배에서 3배까지 감소한 것을 확인할 수 있었다. Amino acid ABC transporter, adenylate kinase, fructokinase, 40k cell wall protein precursor에서는 모두 유전자의 발현량이 현저히 증가한 것을 볼 수 있었다. 이들 유전자는 acid stress에 관여하는 특이적 유전자로 추정된다.

• Molecules and Cells
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• v.22 no.2
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• pp.233-238
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• 2006

Endogenous salicylic acid (SA) and its predominant conjugates, SA 2-O-${\beta}$-D-glucoside (SAG) and the glucose ester of SA (SGE), increase dramatically during plant defense responses. Here I report the isolation and characterization of an Arabidopsis thaliana UDP-glucose:SA glucosyltransferase1 (AtSGT1) gene using a tobacco SGT gene previously reported, whose product catalyzes the formation of both SAG and SGE. The recombinant AtSGT1 protein had significant activities with SA and benzoic acid, and synthesized SAG and SGE. Northern blot analysis showed that AtSGT1 was rapidly induced both by exogenous SA and infection with the bacterial pathogen Pseudomonas syringae, indicating that pathogen-inducible AtSGT1 expression is an early disease response and may be involved in the accumulation of glucosyl SA during pathogenesis.

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.273-276
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• 2000

In the course of surveying the anti-plaque agents for dental caries prevention, the extract of Korean green tea leaves (KGTL) was tested for inhibitory activity against Streptococcus mutans adhering to glass surfaces in the presence of crude glucosyltransferase (GTase). The extracts of KGTL showed a positive inhibitory activity against GTase. The active compound was purified through Sephadex LH-20 and MCI gel CHP-20P columns. A positive reaction was shown in the anisaldehyde-$H_2SO_4$ test, which confirmed the condensed tannin. The inhibitory compound was identified as 3-galloylprocyanidin $B_3$ through IR, negative FAB-mass, and $^{1}H$-NMR spectroscopic analyses. Acetone extract and 3- galloylprocyanidin $B_3$ of KGTL showed inhibitory effect against GTase. The percent of inhibition was determinated to be 71.84% (P<0.01) with 10 mM 3-galloylprocyanidin B3. The 3-galloylprocyanidin $B_3$, which possessed a galloyl, showed a higher inhibitory activity against glucosyltransferase than monomeric (+)-catechin and procyanidine $B_3$ which had no galloyl group.

• KSBB Journal
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• v.19 no.5
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• pp.368-373
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• 2004

The optimal condition for the production of a glucan and a fructan synthesizing enzymes from Leuconostoc mesenteroides NRRL B-1149 were studied based on the different medium compositions. Response surface methodology was applied to find the optimistic condition showing the relationship between the fermentation response (enzyme activities) and the fermentation variable concentrations of yeast extract, peptone concentration, K2HP04 concentration and sucrose. Optimum medium composition for both enzymes production was $0.75\%$ yeast extract, $0.72\%$ peptone, $1\%$ K2HP04 and $2.17\%$ sucrose. Using this medium, the activities produced in culture was 0.90 U/m~ for glucosyltransferase (GTase) and 0.96 U/ml for fructosyltransferase (FTase). After purification of 1149FTase by consecutive chromatographies using Sephadex G-150 and DEAE-Sepharose, a 1149FTase of 210 kDa on $7\%$ polyacrylamide gel was isolated and it synthesized soluble fructan. The 1149GTase showed a band of 180 kDa on $8\%$ polyacrylamide gel after purification using Bio-Gel P-100 gel chromatography and DEAE-Sepharose ion exchange chromatography and it synthesized insoluble glucan. The linkages of polymers were determined by methylation using Hakomori reagent and following NMR analysis. The glucan was composed of a(1~6) and a(1~3) linkages and the fructan was levan.