• Toxicological Research
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• v.31 no.1
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• pp.17-23
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• 2015

Excessive manganese (Mn) in the brain promotes a variety of abnormal behaviors, including memory deficits, decreased motor skills and psychotic behavior resembling Parkinson's disease. Hereditary hemochromatosis (HH) is a prevalent genetic iron overload disorder worldwide. Dysfunction in HFE gene is the major cause of HH. Our previous study has demonstrated that olfactory Mn uptake is altered by HFE deficiency, suggesting that loss of HFE function could alter manganese-associated neurotoxicity. To test this hypothesis, Hfe-knockout ($Hfe^{-/-}$) and wild-type ($Hfe^{+/+}$) mice were intranasally-instilled with manganese chloride ($MnCl_2$ 5 mg/kg) or water daily for 3 weeks and examined for memory function. Olfactory Mn diminished both short-term recognition and spatial memory in $Hfe^{+/+}$ mice, as examined by novel object recognition task and Barnes maze test, respectively. Interestingly, $Hfe^{-/-}$ mice did not show impaired recognition memory caused by Mn exposure, suggesting a potential protective effect of Hfe deficiency against Mn-induced memory deficits. Since many of the neurotoxic effects of manganese are thought to result from increased oxidative stress, we quantified activities of anti-oxidant enzymes in the prefrontal cortex (PFC). Mn instillation decreased superoxide dismutase 1 (SOD1) activity in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice. In addition, Hfe deficiency up-regulated SOD1 and glutathione peroxidase activities. These results suggest a beneficial role of Hfe deficiency in attenuating Mn-induced oxidative stress in the PFC. Furthermore, Mn exposure reduced nicotinic acetylcholine receptor levels in the PFC, indicating that blunted acetylcholine signaling could contribute to impaired memory associated with intranasal manganese. Together, our model suggests that disrupted cholinergic system in the brain is involved in airborne Mn-induced memory deficits and loss of HFE function could in part prevent memory loss via a potential up-regulation of anti-oxidant enzymes in the PFC.

• Journal of Mushroom
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• v.17 no.4
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• pp.185-190
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• 2019

Pleurotus ostreatus No.42, known as the ligninolytic basidiomycetes, showed production of MnP and Lac, but did not show any LiP acitivity in static culture, grown in GPYW liquid medium. Maximum production of MnP (80U/flask) was observed on day 11 of culturing in this medium. Chromatographic purification of MnP included the use of Sepharose CL-6B and Mono-Q. The major MnP isozyme purified by column chromatography was observed to be a 36.4 KDa (single band on SDS PAGE). The 19-amino acid sequence from the N-terminal was determined by protein sequencing to be ATCADGRTTANAACCVLFP. The N-terminal sequence of the major MnP isozyme of P. ostreatus No.42 was found to be the same as a previously reported sequence of an MnP3 isozyme from this fungus.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1540-1548
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• 2012

Manganese peroxidase (MnP) was isolated from the culture filtrate of the wood log mushroom Stereum ostrea (S. ostrea), grown on Koroljova medium, and then purified by ammonium sulfate [70% (w/v)] fractionation, DEAE-cellulose anion exchange chromatography, and Sephadex G-100 column chromatography, with an attainment of 88.6-fold purification and the recovery of 22.8% of initial activity. According to SDS-PAGE the molecular mass of the MnP was 40 kDa. The optimal pH and temperature were found to be 4.5 and $35^{\circ}C$, respectively. The enzyme was stable even after exposure to a pH range of 4.5 to 6.0, and at temperatures of up to $35^{\circ}C$ at a pH of 4.5 for 1h. The $K_m$ and $V_{max}$ values for the substrate phenol red were found to be $8{\mu}m$ and 111.14 U/mg of protein, respectively. The MnP also oxidized other substrates such as guaiacol, DMP, and veratryl alcohol. Sodium azide, EDTA, SDS, $Cu^{2+}$, and $Fe^{2+}$, at 1-5 mM, strongly inhibited enzyme activity, whereas $Ca^{2+}$ and $Zn^{2+}$ increased enzyme activity. The participation of the purified enzyme in the decolorization of dyes suggests that S. ostrea manganese peroxidase could be effectively employed in textile industries.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.178-182
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• 1996

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxidative stresses induced by 0.1 mM of copper ion $(Cu^{++})$ was studied. In aerobic culture condition, yeasts lacking MnSOD (mitochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared withwild type were observed under anaerobic condition. It was found that, under aerobic condition, the supplementation of 0.1 mM copper ioh:(Cu") into culture medium caused the remarkable increase of CuZnSOD but not so significant change in MnSOD. It was also observed that catalase activities appeared to be relatively high in the presence of copper ion in spite of the remarkable reduction of glutathion peroxidase in CuZnSOD-deficient yeasts, but the slight increments of catalase and glutathion peroxidase were detected in MnSOD-deficient strains. It implies that the lack of cytoplasmic SOD could be compensated mainly by catalase. However, these phenomena resulted in the significantincrease of cellular lipid peroxides content in CuZnSOD-deficient yeasts and the slight increment of lipid peroxides in MNSOD-deficient cells. In anaerobic cultivation supplementing copper ion, the cellular enzyme activities of catalase and glutathion peroxidase in SOD-deficient yeasts were slightly increased without any significant changes of lipid peroxides in cell membrane. It suggests that a little amount of free radicals generated by copper ion under anaerobic condition could be sufficiently overcome by catalase as well as glutathion peroxidase.dase.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.783-786
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• 2000

This study was carried out to examine the effect of root-zone temperatures on seedling growth, mineral contents and antioxidative enzyme activities of grafted watermelon. The grafted watermelon seedlings were grown in greenhouse bed for 20 days at root-zone day temperatures of 10, 15, $25^{\circ}C$ while night temperature was maintained at $10^{\circ}C$. Growth such as shoot height, leaf length, leaf number, stem diameter, and fresh and dry weights increased as increasing root-zone temperatures, and leaf area with $25^{\circ}C$($52.79mm^2$) was two times that of control($21.50mm^2$). As increasing the root-zone temperatures, Mn, Ca, Fe contents increased, K, P, Mg were non significant, and Na decreased. The activities of ascorbate peroxidase(APX) and guaiacol peroxidase(GPX) known as antioxidative enzyme were higher at $10^{\circ}C$ than $25^{\circ}C$.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.119.2-119.2
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• 1999

• Journal of Microbiology
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• v.43 no.6
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• pp.569-571
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• 2005

White-rot fungi have the following enzyme systems for lignin degradation: laccase, lignin peroxidase and manganese peroxidase. There are other types of peroxidases related to lignin degradation, one of which we have cloned a cDNA gene of manganese-repressed peroxidase (MrP) in Trametes versicolor isolated in South Korea. The mrp transcript level has been decreased by $1{\mu}M\;of\;Mn^{2+}$.

• Journal of Mushroom
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• v.20 no.1
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• pp.29-33
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• 2022

In this study, five different Lentinula edodes cultivar (Chamaram, Sanbaekhyang, Sanjo 713ho, Sanjo 715ho, Sanjo 718ho) were evaluated for their ability to decolorize Remazol Brilliant Blue R (RBBR) in MEB medium, respectively. Chamaram and Sanjo 713ho decolorized RBBR rapidly in MEB medium within 3 and 5 days. The activities of manganese peroxidase (MnP) and laccase were determined on the MEB medium with and without lignin. Sanjo 713ho resulted the highest ligninolytic enzyme activities on incubation day 1, indicating of 1,213 U/mg of MnP activity and 1,421 U/mg of laccase activity.

• Journal of Life Science
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• v.13 no.6
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• pp.822-828
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• 2003

This study was carried out to investigate the changes of enzymes and micro inorganic nutrients that is associated with flower senescence during flower development in tulip cultivars, ‘Apeldoorn’ and ‘Golden Apeldoorn’. Ribonuclease, peroxidase and protease activities were gradually increased from the stage of early flowering to later Polyphenol oxidase showed the highest activity at stage 5, which the flower was in full bloom indicating that it acts at an initial stage of flower senescence. The protease activity was different in the petal extracts during flower development between the cultivars ‘Apeldoorn’ (red petal) and ‘Golden Apeldoorn’ (yellow petal). This result suggested that protease might relate to pigment biosynthesis in petal of tulip. In contrast to the decrease of inorganic nutrients K, Mn, Zn and P contents during floral development, Ca, Mg and Fe showed the gradual increasement that is similar with ribonuclease, peroxidase and protease. It suggests that they have some interaction during flower senescence.

• YAKHAK HOEJI
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• v.43 no.5
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• pp.598-605
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• 1999

The hot water and mathanol extracts of Artemisia argyi showed considerable cytotoxicities against H9(ATCC HTB 176) cancer cell with IC50 values of $48.6{\;}\mu\textrm{g}/ml$ and $51.9{\;}\mu\textrm{g}/ml$, respectively. These cytotoxicities were found to be dependent on the extract concentrations and culture days. CuZnSOD and MnSOD activities were significantly increased in the cytoplasm and mitochondria fractions of cancer cell, and media in the presence of Artemisia argyi. Such enhanced SOD activities were generally in the range of two to threefolds. In contrast to SOD, catalase and glutathione peroxidase activities were not detected at all. These results suggest that Artemisia argyi have generated $O_2^-$ in the mitochondria and cytoplasm of H9 cancer cell with concurrent induction of CuZnSOD and MnSOD in situ, which dismutate $O_2^-{\}to{\;}H_2O_2$. Without coordinated actions of catalase and/or glutathione peroxidase $H_2O_2$ is easily converted to very toxic OH and these reactive oxygen species together might have induced necrosis and/or apoptosis of H9 cell.