• BMB Reports
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• 제47권9호
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• pp.494-499
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• 2014

NADH:quinone oxidoreductase 1 (NQO1) is known to be involved in the regulation of energy synthesis and metabolism, and the functional studies of NQO1 have largely focused on metabolic disorders. Here, we show for the first time that compared to NQO1-WT mice, NQO1-KO mice exhibited a marked increase of permeability and spontaneous inflammation in the gut. In the DSS-induced colitis model, NQO1-KO mice showed more severe inflammatory responses than NQO1-WT mice. Interestingly, the transcript levels of claudin and occludin, the major tight junction molecules of gut epithelial cells, were significantly decreased in NQO1-KO mice. The colons of NQO1-KO mice also showed high levels of reactive oxygen species (ROS) and histone deacetylase (HDAC) activity, which are known to affect transcriptional regulation. Taken together, these novel findings indicate that NQO1 contributes to the barrier function of gut epithelial cells by regulating the transcription of tight junction molecules.

• 한국환경농학회지
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• 제17권3호
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• pp.239-245
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• 1998

부식형성과정에서 nitroaromatics와 그 환원산물들의 구조에 따른 bound residue형성 양상을 밝히기 위하여 nitrotoluene류, nitrophenol류와 그 환원형태의 화합물 및 nitro기를 가진 살충제 parathion과 amino기를 가진 제초제 asulam을 단독으로 또는 부식을 구성하는 humic monomer들이 존재하는 반응 조건에서 laccase와 HRP를 촉매로 사용하여 그 반응 양상을 조사하였다. Laccase와 HRP를 촉매로 하여 반응시킨 경우, humic monomer의 유무, 종류, nitro기의 결합위치와 수에 관계없이 nitrotoluene류와 nitrophenol류는 laccase와 HRP에 의해 거의 전환되지 않았고, aminotoluene류 및 amino-nitrophenol류는 전부 전환되었다. 일부가 환원된 형태인 amino-nitrotoluene류는 humic monomer에 따라 다른 전환율을 나타내는 데, catechol, syringaldehyde와 protocatechuic acid에서 가장 높은 전환율을 나타내었다. Nitro기가 있는 살충제 parathion은 humic monomer가 존재하는 반응 조건에서 거의 전환되지 않았고, 그 분해산물 4-nitrophenol의 경우도 protocatechuic acid를 제외하고는 거의 전환되지 않았다. Amino기가 있는 제초제 asulam의 경우, humic monomer가 존재하지 않는 조건에서는 거의 전환되지 않았지만 catechol, syringaldehyde, protocatechuic acid 및 caffeic acid의 경우, 비교적 높은 전환율을 나타났다.

• Applied Biological Chemistry
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• 제38권1호
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• pp.37-41
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• 1995

쥐 뇌에서 연령증가에 따른 progesterone의 대사에 대하여 연구하였다. 그 기초실험으로 생후 5일된 암컷 쥐의 뇌를 균질기로 분쇄한 경우와 잘게다진 경우의 실험에서 잘게다진 경우가 더 좋은 활성을 보였으며 쥐뇌 0.3 g, 30분의 표준 실험조건을 결정하였다. 그 결과로 $5{\alpha}$-환원요소의 경우 생후 $5{\sim}14$일에 가장 활성이 높았으며 점차적으로 감소하여 6주 이후에는 거의 일정한 활성을 나타내었다. $3{\alpha}-hydroxy$스테로이드 산화 환원요소$(3{\alpha}-HSOR)$도 $5{\alpha}$-환원요소와 비슷한 형태의 활성을 보였다. 그러나 이때 $3{\beta}-HSOR$의 활성은 연령에 따라 변화가 없이 거의 일정함을 알 수 있었다. 따라서 연령에 따른 $5{\alpha}$-환원대사산물 생성의 감소는 $5{\alpha}$-환원효소의 감소와 $3{\alpha}-HSOR$의 감소에 의하여 일어남을 알 수 있었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.660-664
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• 2000

UK-58,852의 생합성에 관여하는 유전자를 분리하기 위해 Actinomadura roseorufa의 genomic DNA와 E. coli-Streptomyces shuttle cosmid vector인 pOJ446이 genomic library를 만들었다. Genomic library는 dehydratase PCR product와 eryA 유전자를 probe로 하여 sugar 생합성 유전자와 polyketide typel 유전자가 집단으로 존재하는 cosmid pHD54를 분리하였고, 이를 제한 효소인 BamHI, SmaI와 Sonicater를 이용해서 subcloning 하였다. 이들의 염기서열을 부분 분석한 결과, polyketide 생합성에 관여하는 ketoacyl synthase, methylmalonyl acyltransferase, ketoreductase, enolreductase 그리고 PKS loading domain 등 polyketide synthase type I 임을 보여주고 있고, BLAST 분석된 결과를 보면 polyketide synthase 유전자는 rifamycin 생합성 유전자와 유사성이 높다. 그리고 sugar 생합성에 관여하는 유전자로는 oxidoreductase, dTDP-D-glucose 4,6 dehydratase, dTDP-D-glucose synthase 그리고 dTDP-4-keto-6-deoxy-D-glycose 3,5-epimerase으로 구성된 gene cluster를 확인하였다. 그리고 염기서열 분석된 유전자중 dTDP-D-glucose synthase를 발현하여 유전자의 기능을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2363-2367
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• 2014

The association between the NAD(P)H:quinone oxidoreductase 1 (NQO1) gene C609T polymorphism (rs1800566) and gastric cancer has been widely evaluated, but a definitive answer is so far lacking. We first conducted a case-control study to assess this association in a large Han Chinese population, and then performed a meta-analysis to further address this issue. Although our case-control association study indicated no significant difference in the genotype and allele distributions of C609T polymorphism between gastric cancer patients and controls, in the meta analysis involving 4,000 subjects, comparison of alleles 609T and 609C indicated a significantly increased risk (46%) for gastric cancer (95% confidence interval (95%CI) for odds ratio (OR)=1.20-1.79) in individuals with the T allele. The tendency was similar to the homozygote (OR=1.81, 95%CI: 1.16-2.84), dominant models (OR=1.41, 95%CI: 1.12-1.79), as well as recessive model (OR=1.58, 95%CI: 1.06-2.35). Stratified analysis by study design demonstrated stronger associations in population-based than in hospital-based studies. And ethnicity-based analysis demonstrated a significant association in Asians. We conclude that the NQO1 gene C609T polymorphism increases the risk for gastric cancer, especially in Asian populations.

• 한국식품과학회지
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• 제22권7호
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• pp.812-816
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• 1990

쏠비톨 생산을 위해서 Zymomonas mobilis의 Cell wall 투과성을 높인 후 alginate에 고정화 하였다. 투과성을 높이는데 toluene이 가장 효과적인 것으로 나타났으나, 3회의 회분공정을 행한 바 glucose-fructose oxidoreductase의 유출, 손실로 인하며 쏠비톨 생산이 급격히 저하되었다. 효소의 활성도를 장시간 유지하기 위하여 투과성을 높인 cell을 상온에서 1시간 동안 0.25%(v/v)의 glutaraldehyde로 처리한 후 alginate에 고정화 하여 연속공정을 행하였을 때 210시간 동안 높은 전환효율(82%)을 보였으며, 희석비율 $0.18\;h^{-1}$에서 $7.2{\sim}7.5\;g/l-h$의 쏠비톨 productivity를 얻었다. 이는 glutaraldehyde로 처리하지 않고 alginate에 cell을 고정화하였을 때에 비해서 효소의 안정성이 아주 높은 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.488-497
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• 1999

Probing Streptomyces albus ATCC 21838 chromosomal DNA with a proline tRNA sequence resulted in an isolation of a putative integrating element in the 6.4-kb EcoRI fragment. It was found that Streptomyces lividans TK-24 transformed with a cloned DNA fragment on a multicopy plasmid, produced a higher level of spore pigment and mycelial red pigment on a regeneration agar. Furthermore, the transformant S. lividans TK-24 produced a markedly increased level of undecylprodigiosin in a broth culture. A nucleotide sequence analysis of the cloned region revealed several open reading frames homologous to the integrases of integrating plasmids or temperate bacteriophages, signal-transducing regulatory proteins with a conserved ATP-binding domain, oxidoreductases ($\beta$-ketoacyl reductase), and an AraC-like transcriptional regulator. To examine the effect on antibiotic production, each coding region was overexpressed separately from the other genes in the region in S. lividans TK-24 with; pJHS3044 for the expression of the signal-transducing regulatory protein homologue, pJHS3045 for the homologue of oxidoreductase, and pJHS3051 for the homologue of the AraC-like transcriptional regulator. Phenotypic studies of S. lividans TK-24 strains harboring plasmids for the overexpression of individual genes suggested the following effects of the genes on antibiotic production: The oxidoreductase homologue stimulated the production of actinorhodin and undecylprodigiosin, which was influenced by the culture conditions; the homologue of the AraC-like transcriptional regulator was the most effective factor in antibiotic production within all the culture conditions tested; the signal-transducing regulatory protein homologue repressed the effect due to the homologue of the AraC-like transcriptional regulator, however, the antibiotic production was derepressed upon entering the stationary phase.

• Journal of Microbiology
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• 제40권2호
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• pp.125-128
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• 2002

The aerobic respiratory chain of Vibrio alginolyticus possesses two different kinds of NADH oxidase systems, i.e., an $Na^{+}$-dependent NADH oxidase system and an $Na^{+}$-independent NADH oxidase system. When deamino-NADH, which is the only substrate for the $Na^{+}$-dependent NADH oxidase system, was used as a substrate, the maximum activities of $N^{+}$-dependent NADH: quinone oxidoreductase and $Na^{+}$-dependent NADH oxidase were obtained at about 0.06 M and 0.2 M NaCl, respectively. When NADH, which is a substrate for both $Na^{+}$-dependent and $Na^{+}$-independent NADH oxidase systems was used as a substrate, the NADH oxidase activity had a pH optimum at about 8.0. In cGntrastl when deamino-NADH was used as a substrate, the NADH oxidase activity had a pH optimum at about 9.0. On the other handle inside-out membrane vesicles prepared from the wild-type bacterium generated only a very small $\Delta$pH by the NADH oxidase system, whereas inside-out membrane vesicles prepared from Napl, which is a mutant defective in the $Na^{+}$ pump, generated $\Delta$pH to a considerable extent by the NADH oxidase system. On the basis of the results\ulcorner it was concluded that the respiratory chain-linked components of V. atginotyticus affect each other.

• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.79-91
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• 2021

γ-Glutamylcysteine synthetase (Gcs1) and glutathione reductase (Glr1) activity maintains minimal levels of cellular methylglyoxal in Candida albicans. In glutathione-depleted Δgcs1, we previously saw that NAD(H)-linked methylglyoxal oxidoreductase (Mgd1) and alcohol dehydrogenase (Adh1) are the most active methylglyoxal scavengers. With methylglyoxal accumulation, disruptants lacking MGD1 or ADH1 exhibit a poor redox state. However, there is little convincing evidence for a reciprocal relationship between methylglyoxal scavenger genes-disrupted mutants and changes in glutathione-(in)dependent redox regulation. Herein, we attempt to demonstrate a functional role for methylglyoxal scavengers, modeled on a triple disruptant (Δmgd1/Δadh1/Δgcs1), to link between antioxidative enzyme activities and their metabolites in glutathione-depleted conditions. Despite seeing elevated methylglyoxal in all of the disruptants, the result saw a decrease in pyruvate content in Δmgd1/Δadh1/Δgcs1 which was not observed in double gene-disrupted strains such as Δmgd1/Δgcs1 and Δadh1/Δgcs1. Interestingly, Δmgd1/Δadh1/Δgcs1 exhibited a significantly decrease in H2O2 and superoxide which was also unobserved in Δmgd1/Δgcs1 and Δadh1/Δgcs1. The activities of the antioxidative enzymes erythroascorbate peroxidase and cytochrome c peroxidase were noticeably higher in Δmgd1/Δadh1/Δgcs1 than in the other disruptants. Meanwhile, Glr1 activity severely diminished in Δmgd1/Δadh1/Δgcs1. Monitoring complementary gene transcripts between double gene-disrupted Δmgd1/Δgcs1 and Δadh1/Δgcs1 supported the concept of an unbalanced redox state independent of the Glr1 activity for Δmgd1/Δadh1/Δgcs1. Our data demonstrate the reciprocal use of Eapx1 and Ccp1 in the absence of both methylglyoxal scavengers; that being pivotal for viability in non-filamentous budding yeast.

• Animal Bioscience
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• 제37권2_spc호
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• pp.396-403
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• 2024

Objective: Monofluoroacetate (MFA) is a potent toxin that blocks ATP production via the Krebs cycle and causes acute toxicity in ruminants consuming MFA-containing plants. The rumen bacterium, Cloacibacillus porcorum strain MFA1 belongs to the phylum Synergistota and can produce fluoride and acetate from MFA as the end-products of dehalorespiration. The aim of this study was to identify the genomic basis for the metabolism of MFA by this bacterium. Methods: A draft genome sequence for C. porcorum strain MFA1 was assembled and quantitative transcriptomic analysis was performed thus highlighting a candidate operon encoding four proteins that are responsible for the carbon-fluorine bond cleavage. Comparative genome analysis of this operon was undertaken with three other species of closely related Synergistota bacteria. Results: Two of the genes in this operon are related to the substrate-binding components of the glycine reductase protein B (GrdB) complex. Glycine shares a similar structure to MFA suggesting a role for these proteins in binding MFA. The remaining two genes in the operon, an antiporter family protein and an oxidoreductase belonging to the radical S-adenosyl methionine superfamily, are hypothesised to transport and activate the GrdB-like protein respectively. Similar operons were identified in a small number of other Synergistota bacteria including type strains of Cloacibacillus porcorum, C. evryensis, and Pyramidobacter piscolens, suggesting lateral transfer of the operon as these genera belong to separate families. We confirmed that all three species can degrade MFA, however, substrate degradation in P. piscolens was notably reduced compared to Cloacibacillus isolates possibly reflecting the loss of the oxidoreductase and antiporter in the P. piscolens operon. Conclusion: Identification of this unusual anaerobic fluoroacetate metabolism extends the known substrates for dehalorespiration and indicates the potential for substrate plasticity in amino acid-reducing enzymes to include xenobiotics.