• 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.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.46-51
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• 1987

In order to increase the production of tryptophan by maximizing expression of recombinant trp plasmid, Klebsiella pneumoniae KC 105(pheA tyrA trpE trpR tyrR) was genetically modified. KC 107, inosine monophospate(IMP) auxotroph from KC 105 and KC 108, histidine(His) auxotroph from KC 107 were also derived respectively to increase phosphoribosylpyrophosphate(PRPP) production which is required for tryptophan biosynthesis. From KC 107 phosphoribosylpyrophosphate consumption which is required for tryptophan biosynthesis. From KC 107 and KC 108, KC 109 and KC 110, both arginine auxotrophs were derived respectively. To investigate the expression of recombinant trp plasmid in the selected K. pneumoniae mutants, the auxotrophic mutants were transformed with recombinant trp plasmids pSC 101-$trpE^{FBR}$, pSC 101-trpL(.DELTA.att) $trpE^{FBR}$ (pSC 101-trp-AF). Amount of tryptophan produced and activities of tryptophan synthase of $trpR^{-}$ mutant (KC 100) and $tyrR^{-}$ mutnat(KC 105) containing recombinant plasmid pSC 101-trp operon were increased by 30-40% as compared with KC 99(pheA tyrA trpE) containing recombinant plasmid pSC 101-trp operon. Activities of tryptophan synthase and production of tryptophan of KC 108 ($His^{-}$) and KC 109($Arg^{-}$) containing recombinant plasmid pSC 101-trp operon were increase by two-fold as compared with KC 107 containing pSC 101-trp operon.

• The Korean Journal of Food And Nutrition
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• v.14 no.4
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• pp.329-332
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• 2001

The antimutagenic activity of resveratrol on the mutagenicity induced by Trp P-1 (3-amino-1,4-dime-thyl-5H-pyrido{4,3-b}indole) was studied using the Ames test with Salmonella typhimurium TA98 and 100. Trp P-1 showed strong mutagenecity in S. typhimurium TA98, but was higly decreased mutagenecity in S. typhimurium TA100. This result suggests that the mutagenecity of Trp P-1 can be mainly induced by the DNA lesions causing frame shift. Resveratrol itself did not show antibacterial effect upon 300 $\mu\textrm{g}$/assay. Resveratrol showed the strongest inhibitory effect with dose dependent manner on the mutagenicity induced by Trp P-1. The inhibition rates of resveratrol at concentration of 2, 10, 25, 50, 100, 300 $\mu\textrm{g}$/assay were 13%, 37%, 52%, 65%, 81%, 89%, respectively.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.9-12
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• 1985

As a part of the host cell development for a amplified recombinant trp operon, $aroP^-$ mutation was introduced in a E. coli host strain. $aroP^-$ mutation was induced by transposon Tn10 and transduced into the E. coli host cell by bacteriophage P1Kc. The effect of $aroP^-$ mutation on the excretion of tryptophan in E. coli $trpR^{-ts}/ColE_1 -trp^+$ cells was investigated. Mutant lacking the general aromatic transport system was resistant to ${\beta}-2-thienylalanine\;(2{\times}10^{-4}\;M)$, p-fluorophenylalanine $(2{\times}10^{-4}M)$, or 5-methyltryptophan $(2{\times}10^{-4}\;M.)[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain was reduced considerably as compared with $aroP^+$ counterpart. The rate of $[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain treated with $NaN_3(3{\times}10^{-2}\;M)$ was much less affected than that of $aroP^+$ counterpart. The $aroP^-$ transductants increased the tryptophan excretion from E. coli $trpR^{-ts}/ColE_1 -trp^+$ four times more than $aroP^+$ counterpart.

• Bulletin of Food Technology
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• v.12 no.2
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• pp.26-38
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• 1999

조리가공 중 생성되는 주요 발암성 이환방향족아민(heterocyclic aromatic amine)인 Trp-P-1 및 Trp-P-2가 human 및 rat keratinocytes에 대해 나타내는 세포 독성을 colony expansion법의 의해 조사, 비교하였다. 특히 Trp-P-2는 human keratinocytes에 대해서는 독성을 나타내지 않은데 반해 rat keratinocytes(계대수 2-5)에 대해서는 독성을 나타내는 선택성을 나타내었다. 이러한 Trp-P-2의 종(species)간 독성감수성 차이가 대사 효소계 활성이나 mutagenic activation상의 차이에 기인되는지를 살펴본 결과, CYP4501As 및 독성감수성 차이가 크게 나타났던 human 및 rat keratinocytes의 microsome에서 거의 같았다. 이와 같은 결과는 CYP4501A1 및 CYP1B1의 mRNA의 발현정도를 northernblot에 의해 살펴보았던 결과에서도 일치하였다. 반면 Trp-P-2의 대사활성화 및 해독화에 관여하는 효소인 N.O-acetyltransferase(NAT)활성은 rat keratinocytes보다 human keratinocytes에서 높았다. 일반적으로 독성물질의 해독화에 관여하는 glutathione S-transferase(GST) 또한 rat keratinocytes보다 human keratinocytes에서 높게 나타났다. Trp-P-2가 mutagenic metabolite로 활성화되는 정도를 salmonella microsome microsuspension assay로 살펴본 결과, 독성 감수성 차이가 크게 나타났던 human 및 rat keratinocytes간의 활성은 비슷한 것으로 나타났다. DNA 및 단백질 adduct형성능의 경우, human 및 rat keratinocytes간 DNA adduct형성능에는 차이가 없었고, 단백질 adduct형성능의 경우만 Trp-P-2에 대한 독성감수성 정도가 컸던 rat keratinocytes가 다른 세포들에 비해 크게 나타났다. 이상의 결과를 종합해 볼 때, CYP1A- 또는 CYP1B1-관련 마이크로솜 효소활성이나 mutagenic activation은 human 및 rat keratinocytes간에 나타났던 독성 감수성의 차이를 설명할 수 없으며, 해독화에 관여하는 효소활성이 종간 관찰되었던 독성 감수성의 차이에 더 중요한 역할을 하는 것으로 보인다.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.188-194
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• 1994

The inhibitory effects of rice extract on mutagenicity induced by 3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole(Trp-P-1), 3-amino-1-methyl-5H-pyrido [4,3-b]indole(Trp-P-2), sodium azide(SA), 2-nitrofluorene(2NF), mitomycin C(MMC), aflatoxin $B_1(AFB_1)$ and 4-nitroquinoline oxide(4-NQO) were investigated using Salmonella typhimurium reversion assay, SOS chromotest and spore rec-assay. In Salmonella typhimurium reversion assay, methanol extract from brown rice (Illpumbyeo, Japonica variety) showed the highest inhibitory effect among other extracting solvent including hexane, chloroform and water. Methanol extract showed stronger inhibitory effect, above 85%, on indirect-acting mutagens(Trp-P-1, Trp-P-2 and $AFB_1$) than those on direct-acting mutagens(4-NQO, 2NF). In SOS chromotest, methanol extracts showed $77.6{\sim}88.9%$ effects on SOS function induced by Trp-P-1, Trp-P-2, $AFB_1$ and 4-NQO. In spore rec-assay, methanol extracts inhibited the mutagenicity induced by $AFB_1$ and MMC. As the concentration of methanol extract increased, inhibitory effect on mutagenicity increased but reached at steady state as inhibition rate of 90% when the concentration was above 5 mg/plate. In inhibitory effects of methanol extracts by various rice varieties, all of 11 varieties turned out to have inhibitory effect on mutagenicity. There was no significant difference (p>0.05) in inhibitory effect of methanol extracts between brown and white rice against Trp-P-1, but showed difference (p<0.05) against 4-NQO.

• Journal of Food Hygiene and Safety
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• v.7 no.4
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• pp.161-168
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• 1992

On the mutagenicity induced by 3-amino-l,4-dimethyl-5-H-pyrido[4,3-b]indol (Trp-P-1) and 2-aminotluorene (2-AF), the antimutagenic effects of edible muntain herb juices were examined by the Ames assay using Salmonella typhimurium TA98 and TA100. Juices prepared from aralia bud, small water dropwort, mugwort, roots of belltlower and sedum didn't have mutagenicity. Most of sample juices showed the antimutagenicity. Especially, juices prepared from aralia bud, small water dropwort and mugwort were found to possess strong antimutagenic effects. Sedum was moderatly effective and root of belltlower had little effect on mutagenicity caused by Trp-P1 and 2-AF. The experimental results with TA98 were similar to those with TA100 in the antimutagenicity test of edible mountain herb juices. In this study, antimutagenicity on Trp-P-1 was more effective than that on 2-AF.

• Korean journal of food and cookery science
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• v.16 no.5
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• pp.390-393
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• 2000

Desmutagenic effects of water-soluble and ethanol-soluble extracts of dried green tea toward the mutagenicity of 4-nitroquinoline-N-oxide(4-NQO) and 3-Amino-1,4-dimethyl-5H-pyrido［4,3-b］indole(Trp-P-1) in streptomycin-dependent SD510 strains of Salmonella typhimurium TA98 were investigated. Inhibition effects toward the mutagenicity of 4-NQO and Trp-P-1 of water-soluble and ethanol-soluble extracts from green tea were high as increase of concentration of extracts. Desmutagenic effects toward 4-NQO of water-soluble and ethanol-soluble extracts from green tea harvested in May and August were up to 93% in 1,000 $\mu\textrm{g}$ of extract/plate. Desmutagenic effects toward Trp-P-1 of ethanol-soluble extracts from green tea were 53.3∼92.1%, but the effects of water-soluble extracts decreased as increase of concentration of extracts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1371-1377
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• 2006

Gene polymorphisms that are associated with sodium homeostasis in the body, such as $\alpha-adducin$ (ADDI, Gly460Trp), angiotensinogen (AGT, Met235Thr), and angiotensin converting enzyme (ACE, Ins/Del) may increase the risk for the development of hypertension. The purpose of this study was to elucidate the relationship between the singular and combined effects of ADD1, AGT, ACE genotypes, and blood pressure in elderly population. Moreover, we examined the interaction of sodium intake and polymorphisms of aforementioned genes and their effects on blood pressure. Among one hundred and nine female subjects, aged 60 and over (mean 75.9 yr), the major alleles for ADD1, AGT, and ACE polymorphisms in the studied population were Gly (66.1%), Thr (64.2%), Ins (83.5%), respectively. Analysis on the combined effects of genetic variation showed that subjects who were both ADD1 Trp/Trp and ACE Del/Del homozygotes had significantly higher systolic blood pressure (p=0.01). Similarly, ACE Del/Del homozygotes who had AGT Met allele had significantly higher diastolic blood pressure (p<0.001). However, in single-gene analyses, no association was found between any specific genotype and blood pressure. In subjects with low sodium intake, ADD1 Trp/Trp homozygotes had significantly higher systolic blood pressure than subjects who had ADD1 Gly allele (138 mmHg vs. 127 mmHg, p=0.03). There was no difference in blood pressure between ADD1 Trp/Trp and ADD1 Gly/Gly or Gly/Trp, in subjects with high sodium intake. In summary, this study shows that interactions between the ADD1, AGT and ACE genes influence systolic and diastolic blood pressure in elderly subjects, and dietary sodium intake can modulate the effects of ADD1 Gly460Trp polymorphisms on systolic blood pres sure.

• Journal of Life Science
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• v.26 no.12
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• pp.1376-1382
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• 2016

Xylitol is widely used in the food and medical industry. It is produced by the reduction of xylose (lignocellulosic biomass) in the Saccharomyces cerevisiae strain, which is considered genetically safe. In this study, the expression system of the GRE3 (YHR104W) gene that encodes xylose reductase was constructed to efficiently produce xylitol in the S. cerevisiae strain, and the secretory production of xylose reductase was investigated. To select a suitable promoter for the expression of the GRE3 gene, pGMF-GRE3 and pAMF-GRE3 plasmid with GAL10 promoter and ADH1 promoter, respectively, were constructed. The mating factor ${\alpha}$ ($MF{\alpha}$) signal sequence was also connected to each promoter for secretory production. Each plasmid was transformed into S. cerevisiae $SEY2102{\Delta}trp1$, and $SEY2102{\Delta}trp1$/pGMF- GRE3 and $SEY2102{\Delta}trp1$/pAMF-GRE3 transformants were selected. In the $SEY2102{\Delta}trp1$/pGMF-GRE3 strain, the total activity of xylose reductase reached 0.34 unit/mg-protein when NADPH was used as a cofactor; this activity was 1.5 fold higher than that in $SEY2102{\Delta}trp1$/pAMF-GRE3 with ADH1 as the promoter. The secretion efficiency was 91% in both strains, indicating that most of the recombinant xylose reductase was efficiently secreted in the extracellular fraction. In a baffled flask culture of the $SEY2102{\Delta}trp1$/pGMF-GRE3 strain, 12.1 g/l of xylitol was produced from 20 g/l of xylose, and ~83% of the consumed xylose was reduced to xylitol.