• 제목/요약/키워드: scavengers

검색결과 198건 처리시간 0.021초

Methylglyoxal-Scavenging Enzyme Activities Trigger Erythroascorbate Peroxidase and Cytochrome c Peroxidase in Glutathione-Depleted Candida albicans

  • Kang, Sa-Ouk;Kwak, Min-Kyu
    • 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.

면직물의 저$\cdot$Formaldehyde D.P. 가공 (Low Formaldehyde Release D.P. Finish on Cotton Fabrics)

  • 김성련;류효선;노형은
    • 한국의류학회지
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    • 제10권3호
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    • pp.71-81
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    • 1986
  • In order to control the formaldehyde release from D.P. finished fabric, cotton fabric was padded in DMDHEU resin bath containing either $Zn(NO_3)_2$ or $MgCl_2$ catalyst and a form-aldehyde scavenger like Glycerol, Sorbitol, Formamide, Polyvinyl alcohol (PVA, n= 2000) or diols, then dried and cured. The results are as follows : 1. When Lewis acid catalyst like $Zn(NO_3)_2$ or $MgCl_2$ was added in pad bath, the fabric finished with $Zn(NO_3)_2$ catalyst released the lower formaldehyde than with $MgCl_2$. 2. When the effect of pad bath pH was examined with varying the kinds of catalyst and the scavenger, it was found that the pad bath pH influenced on the amount of formaldehyde release and the optimum pad bath pH is at 4.3. Especially, in case of finishing at pad bath pH 4.3 with adding Formamide, the amount of formaldehyde release was decreased by about $45\~$35\%$ with $Zn(NO_3)_2$, while by about $20\~$45\%$ with $MgCl_2$ catalyst. In case of varying the concentration of a scavenger (Formamide), $1\%$ concentration of a scavenger was found to be the optimum level ana the higher the curing temperature up to $180^{\circ}C$, the lesser the amount of formaldehyde release were observed. 3. When the diol was used as scavenger, the amount of formaldehyde release was decreased by about $40\~$50\%$, but the longer the intramolecular length between OH groups, the lessor the amount of decrease of formaldehyde release were observed. 4. When the mixture of scavengers (Formamide and Glycerol) was added in the pad bath, .synergistic effect on formaldehyde release between the two scavengers wasn't observed. 5. The tensile strength of the resin finished fabric was reduced with increasing the pad lath pH and was influenced by the kind of scavengers, and the tensile strength was severely reduced when scavengers, especially Formamide, was added. The wrinkle recovery property is generally improved by resin finish on cotton fabric. When Formamide was added, the wrinkle recovery property is slightly decreased compared with that of the fabrics resin finished without a scavenger, and when polyol was added, the wrinkle recovery property showed almost no change.

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진피 콜라겐의 노화에 대한 활성산소와 자외선의 영향 (THE ROLE OF REACTIVE OXYGEN SPECIES ON UVA-INDUCED AGING OF DERMAL COLLAGEN)

  • 강상진;홍성돈;조완구;채쾌
    • 대한화장품학회지
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    • 제18권1호
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    • pp.64-80
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    • 1992
  • Collagen은 세포 외에 존재하며, 분자의 수명이 매우 긴 단백질이므로, 노화와 관련된 비효소적 당화의 대상으로 많은 관심이 모아지고 있다. 본 연구에서는 진피 collagen의 비효소적 당화와 분해 및 가교결합에 대한 자외선(UVA)과 활성산소종들의 영향을 검토하였다. 암소 피부로부터 얻은 collagen 과 glucose의 혼합물에 몇가지 활성산소 소거제를 첨가하고 UVA를 조사하여 비효소적 당화, 단백질 분해, 가교결합의 정도를 관찰하였다. 비효소적 당화는 자외선에 의해 증가되지 않았으며, 수퍼옥사이드 라디칼과 일중항 산소의 소거제에 의해서는 감소하였으나, 히드록시 라디칼 소거제에 의해서는 변화가 없었다. 단백질 분해와 가교결합은 자외선에 의해 증가되었으며, 분해는 세가지 활성산소의 소거제 모두에 의해 감소되었으나, 가교결합은 특히 히드록시 라디칼 소거제의 영향이 컸다. 즉 수퍼옥사이드 라디칼과 일중항 산소는 자외선과는 관계 없이 당의 자동산화에 의해 발생되어 당화로 인한 변화의 초기 단게에 관여하고, 반응의 뒷부분에서는 당단백질과 자외선에 의해 만들어진 히드록시 라디칼이 주된 역할을 하고 있다. 상기의 결과로부터 활성산소종들과 자외선은 다른 조직 및 세포물질들을 손상시키듯이 노화와 관련된 collagen 변화를 증가시키는 것을 알 수 있었다. 이는 자외선 차단제와 함께 활성산소 소거 물질들을 외용도포하는 것이 태양광선의 해로운 영향으로부터 진피를 보호하는데 도움이 될 수 있음을 의미한다.

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Oxidative modification of ferritin induced by methylglyoxal

  • An, Sung-Ho;Lee, Myeong-Seon;Kang, Jung-Hoon
    • BMB Reports
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    • 제45권3호
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    • pp.147-152
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    • 2012
  • Methylglyoxal (MG) was identified as an intermediate in non-enzymatic glycation and increased levels were reported in patients with diabetes. In this study, we evaluated the effects of MG on the modification of ferritin. When ferritin was incubated with MG, covalent crosslinking of the protein increased in a time- and MG dose-dependent manner. Reactive oxygen species (ROS) scavengers, $N-acetyl-_L-cysteine$ and thiourea suppressed the MG-mediated ferritin modification. The formation of dityrosine was observed in MG-mediated ferritin aggregates and ROS scavengers inhibited the formation of dityrosine. During the reaction between ferritin and MG, the generation of ROS was increased as a function of incubation time. These results suggest that ROS may play a role in the modification of ferritin by MG. The reaction between ferritin and MG led to the release of iron ions from the protein. Ferritin exposure to MG resulted in a loss of arginine, histidine and lysine residues. It was assumed that oxidative damage to ferritin caused by MG may induce an increase in the iron content in cells, which is deleterious to cells. This mechanism, in part, may provide an explanation or the deterioration of organs under diabetic conditions.

DNA Cleavage Induced by the Reaction of Salsolinol with Cu,Zn-Superoxide Dismutase

  • Kang, Jung-Hoon
    • Bulletin of the Korean Chemical Society
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    • 제28권12호
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    • pp.2329-2332
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    • 2007
  • Salsolinol, endogenous neurotoxin, is known to be involved in the pathogenesis of Parkinson's disease (PD). In the present study, we have investigated the oxidative damage of DNA induced by the reaction of salsolinol with Cu,Zn-SOD. When plasmid DNA incubated with salsolinol and Cu,Zn-SOD, DNA cleavage was proportional to the concentrations of salsolinol and Cu,Zn-SOD. The salsolinol/Cu,Zn-SOD system-mediated DNA cleavage was significantly inhibited by radical scavengers such as mannitol, ethanol and thiourea. These results indicated that free radicals might participate in DNA cleavage by the salsolinol/Cu,Zn-SOD system. Spectrophotometric study using a thiobarbituric acid showed that hydroxyl radical formation was proportional to the concentration of salsolinol and was inhibited by radical scavengers. These results indicated that hydroxyl radical generated in the reaction of salsolinol with Cu,Zn-SOD was implicated in the DNA cleavage. Catalase and copper chelators inhibited DNA cleavage and the production of hydroxyl radicals. These results suggest that DNA cleavage is mediated in the reaction of salsolinol with Cu,Zn-SOD via the generation of hydroxyl radical by a combination of the oxidation reaction of salsolinol and Fenton-like reaction of free copper ions released from oxidatively damaged SOD.

Mouse Melanoma Cell Migration is Dependent on Production of Reactive Oxygen Species under Normoxia Condition

  • Im, Yun-Sun;Ryu, Yun-Kyoung;Moon, Eun-Yi
    • Biomolecules & Therapeutics
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    • 제20권2호
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    • pp.165-170
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    • 2012
  • Cell migration plays a role in many physiological and pathological processes. Reactive oxygen species (ROS) produced in mammalian cells influence intracellular signaling processes which in turn regulate various biological activities. Here, we investigated whether melanoma cell migration could be controlled by ROS production under normoxia condition. Cell migration was measured by wound healing assay after scratching confluent monolayer of B16F10 mouse melanoma cells. Cell migration was enhanced over 12 h after scratching cells. In addition, we found that ROS production was increased by scratching cells. ERK phosphorylation was also increased by scratching cells but it was decreased by the treatment with ROS scavengers, N-acetylcysteine (NAC). Tumor cell migration was inhibited by the treatment with PD98059, ERK inhibitor, NAC or DPI, well-known ROS scavengers. Tumor cell growth as judged by succinate dehydrogenase activity was inhibited by NAC treatment. When mice were intraperitoneally administered with NAC, the intracellular ROS production was reduced in peripheral blood mononuclear cells. In addition, B16F10 tumor growth was significantly inhibited by in vivo treatment with NAC. Collectively, these findings suggest that tumor cell migration and growth could be controlled by ROS production and its downstream signaling pathways, in vitro and in vivo.

The Screening of Nitrite Scavenging Effect of Marine, Algae and Active Principles of Ecklonia Stolonifera

  • CHOI Jae Sue;LEE Ji Hyeon;JUNG Jee Hyung
    • 한국수산과학회지
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    • 제30권6호
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    • pp.909-915
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    • 1997
  • The nitrite scavenging effect of methanol extracts of marine algae were evaluated to discover new natural nitrite scavengers. Among the tested seaweeds, Ecklonia stolonifera, an edible brown algae, showed the strongest scavenging effect. The MeOH extract was then sequentially partitioned into $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, EtOAc, n-BuOH, and $H_2O$ layers. The EtOAc and n-BuOH fraction demonstrated high levels of nitrite-scavenging activity while the $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, and $H_2O$ fractions were inactive. A column chromatography of the EtOAc fraction through silica gel and Sephadex LH-20 yielded phloroglucinol and a new compound tentatively named phlorotannin A. The nitrite scavenging activity of phloroglucinol $(IC_{50}=3.9{\mu}g/ml)$ was more potent than that of L-ascorbic acid $(IC_{50}=65.0{\mu}g/ml)$. However, phlorotannin A $(IC_{50}=193.2{\mu}g/ml)$ showed only low levels of activity. From the above results, it is possible to suggest that both the MeOH extract and their fractions and isolated phloroglucinol and phlorotannin A obtained from E. stolonifera may be applicable as scavengers of nitrite, which is a precursor for the formation of carcinogenic N-nitroso compounds.

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Suppression of Arsenic Trioxide-induced Apoptosis in HeLa Cells by N-Acetylcysteine

  • Han, Yong Hwan;Kim, Sung Zoo;Kim, Suhn Hee;Park, Woo Hyun
    • Molecules and Cells
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    • 제26권1호
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    • pp.18-25
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    • 2008
  • Arsenic trioxide (ATO) can affect many biological functions such as apoptosis and differentiation in various cells. We investigated the involvement of ROS and GSH in ATO-induced HeLa cell death using ROS scavengers, especially N-acetylcysteine (NAC). ATO increased intracellular ${O_2}^{{\cdot}-}$ levels and reduced intracellular GSH content. The ROS scavengers, Tempol, Tiron and Trimetazidine, did not significantly reduce levels of ROS or GSH depletion in ATO-treated HeLa cells. Nor did they reduce the apoptosis induced by ATO. In contrast, treatment with NAC reduced ROS levels and GSH depletion in the ATO-treated HeLa cells and prevented ATO-induced apoptosis. Treatment with exogenous SOD and catalase reduced the depletion of GSH content in ATO-treated cells. Catalase strongly protected the cells from ATO-induced apoptosis. In addition, treatment with SOD, catalase and NAC slightly inhibited the G1 phase accumulation induced by ATO. In conclusion, NAC protects HeLa cells from apoptosis induced by ATO by up-regulating intracellular GSH content and partially reducing the production of ${O_2}^{{\cdot}-}$.