• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.45-52
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• 2005

The manganese peroxidase (mnp5) from white-rot fungus Phanerochaete chrysosporium has been heterologously expressed in the methylotrophic yeast Pichia pastoris. The majority of the rMnP5 (recombinant MnP5) produced by P. pastoris exhibited an approximate molecular mass 45 kDa considerably larger than that of the predicting mnp5 due to two glycosylation sites of mnp5. After site direct mutation treatment, the effect of N-linked hyperglycosylation was examined by enzyme activity. Analysis by sodium dodesyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Coomassie Brilliant Blue (CBB) staining revealed a major protein band with a molecular mass of 37 kDa. Enzyme activity of M-rMnP5 (mutant recombinant MnP5) was similar to that of rMnP5, indicating that hyperglycosylation did not affect the active site. In this work, active mnp5 was successfully expressed in P. pastoris, suggesting that P. pastoris has potential capability of producing active heme-containing proteins.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.1-20
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• 1997

목재를 분해시키는 담자균류들은 목재 및 목질복합체에 쉽사리 침투하여 복잡한 리그노셀룰로오스 복합체를 분해시킨다. 이러한 분해에는 많은 효소시스템들이 복합적으로 작용하면서 상호 협동하는 것으로 보고되고 있다. 지금까지 일려진 효소들은 통상 3개의 그룹으로 나눌 수 있는데 그 하나는 목재성분을 직접적으로 공격하는 효소균들, 예를 들면 cellulase complex, laccase(LAC), lignin peroxidase(LIP), horse-radish peroxidase(HRP), manganese-independent peroxidase(MIP) 및 protocatechuate 3,4-dioxygenase(PCD) 등이 있고, 두번째 그룹으로서 manganese-dependent peroxidase(MnP), aryl alcohol oxidase(AAO) 및 glyoxal oxidase(GLO) 등인데, 이들 효소들은 목질을 직접적으로 공격하지 않고 제1그룹의 효소들과 협동하여 작용하는 것으로 알려지고 있다. 제3그룹의 효소들은 glucose oxidase(GOD) 및 cellobiose : quinone oxidoreductase(CBQ)로서 feedback type의 효소들로서 목재고분자의 분해시 대사의 고리를 결합시켜 주는 매우 중요한 기능을 하는 효소군들이다. 그러나 이 이외에도 다른 분해기구가 밝혀지고 있으며 기타 효소들에 의한 리그노셀룰로오스의 분해반응기구의 해명에는 상당한 시간이 걸릴 것으로 사료된다.

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

• 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.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.67-71
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• 2001

Effects of exposure to a neurotoxicant, fenitrothion on antioxidant enzyme activities in Chironomus riparius Mg. (Diptera, Chironomidae) larvae were evaluated under laboratory conditions. Exposure to this chemical led to an increase of cupper, zinc type superoxide dismutase and manganese type superoxide dismutase activities and to a decrease of glutathion peroxidase activity. An activation of catalase was observed in the larvae exposed to high fenitrothion concentration. The response of superoxide dismutase was rapid and sensitive to low chemical concentrations, but changes in catalase, total peroxidase and glutathion peroxidase were less sensitive. In this study, antioxidant enzyme activities in Chironomus riparius larvae were identified as pertinent biomarkers for environmental monitoring.

• Journal of Mushroom
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• v.19 no.4
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• pp.316-321
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• 2021

Ligninolytic enzymes were produced by Pleurotus ostreatus No.42, cultivated in a new kind of bioreactor that has a rotating draft tube with a helical ribbon. Maximum laccase (Lac) production (about 8,200 U/bioreactor) was reached after 3 days of incubation, then production decreased. Production of manganese peroxidase (MnP) in this fermenter reached a maximum level of about 8,400 U/bioreactor after 6 days of incubation. Lignin peroxidase (LiP) was not detected under these growth conditions. These results indicate that the rotary draft tube bioreactor (RTB) is compatible with large scale production of ligninolytic enzymes. MnP produced under these fermentation conditions was purified via a multistep process that included chromatography on Sepharose CL-6B, prep grade Superdex 75, and Mono-Q. This major isoenzyme was confirmed to have an apparent molecular weight of 36,400 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and its isoelectric point (IEF) was determined to be 3.95. N-terminal sequencing of the major isoenzyme from this fermentation was identical to that reported for an MnP3 isoenzyme isolated under different cultivation conditions, including stationary and shaking culture.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.87-93
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• 2006

This study was done to know a kind and change (transition) of enzymes produceed by Streptomyces halstedii ssp. scabies SA1-27 and Streptomyces violaceusinger C1-6 which showed good lignolytic activity and a good decolorization ratio of remazol brilliant blue R(RBBR) dye. These strains were isolated from soil and identified by the author. The basal medium containg 0.2% glucose was used to measure enzyme activity, Lignin peroxidase 1 (Lip 1) was measured by the methods of Choi, and Bourbonnais and Paice. Lignin peroxidase 2 (Lip 2) was measured by the methods of Ishida et al and Ramachandra et al using 2.4-dichlorophenol(2.4 DCP), manganese peroxidase(Mnp), veratryl alcohol oxidase (VAO), and laccase. They were measured by each of the methods of Choi and Paszczynski et al, and Bourbonnais and Paice, and De Jong et al. In the results, the kind of enzymes produced by Streptomyces halstedii ssp. scabies SA1-27 were Lip 1, Lip 2, VAO, and laccase, and their activities indicated the highest value as each 4.95 nmol/mg protein, $8.45({\times}100^{-3})unit$, 10.25 nmol/mg protein, 9.20 nmol/mg protein on the sixth day of the culture and decreased gradually over time. The kind of enzymes produced by Streptomyces violaceusinger C1-6 were Lip 1, Lip 2, Mnp, VAO, and laccase, and their activities indicated the highest value as each 4.90 nmol/mg protein, $13.85({\times}100^{-3})unit$, 3.10 nmol/mg protein, 11.30 nmol/mg protein, 4.45 nmol/mg protein on the sixth day of the culture and decreased gradually over time. Consequently, the author knew the fact that there were few differences in the kind and quantity of enzymes produced by the two Streptomyces strains, but all enzyme activities indicated the highest value on the sixth day of the culture and decreased gradually over time.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1190-1195
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• 2004

In recent years, there has been an intensive research on decolorization of dye and textile wastewater by various fungal strains. In this study, the decolorization ability of three commercial dyes, acid yellow 99, acid blue 350, and acid red 114, were investigated using 10 fungal strains. Among the fungal strains tested, Trametes versicolor KCTC 16781 completely decolorized all dyes in both solid and liquid experiments, and was also able to decolorize the mixture of those three dyes in liquid experiments. The secretion of the ligninolytic enzymes into the extracellular medium during decolorization by T versicolor KCTC 16781 was also studied. No lignin peroxidase activity was detected, and manganese peroxidase and laccase activities were investigated.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.803-813
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• 2015

The growth of Irpex lacteus F17 and manganese peroxidase (MnP) production in a selfdesigned tray bioreactor, operating in solid-state conditions at a laboratory scale, were studied. The bioreactor was divided into three layers by three perforated trays. Agroindustrial residues were used both as the carrier of bound mycelia and as a nutrient medium for the growth of I. lacteus F17. The maximum biomass production in the bioreactor was detected at 60 h of fermentation, which was consistent with the CO₂ releasing rate by the fungus. During the stationary phase of fungal growth, the maximum MnP activity was observed, reaching 950 U/l at 84 h. Scanning electron microscopy images clearly showed the growth situation of mycelia on the support matrix. Furthermore, the MnP produced by I. lacteus F17 in the bioreactor was isolated and purified, and the internal peptide sequences were also identified with mass spectrometry. The optimal activity of the enzyme was detected at pH 7 and 25℃, with a long half-life time of 9 days. In addition, the MnP exhibited significant stability within a broad pH range of 4-7 and at temperature up to 55℃. Besides this, the MnP showed the ability to decolorize the polymeric model dye Poly R-478 in vitro.

• Korean Journal of Microbiology
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• v.48 no.3
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• pp.225-227
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• 2012

Lignin degrading enzymes from white rot fungi show broad substrate specificities, and therefore they can degrade variety of recalcitrant compounds. We have used three different protocols for the generation of immobilized laccase and manganese peroxidase crude enzymes from the genetically transformed strains of Merulius tremellosus Fr. These immobilized enzymes were used in the decolorization of Remazol Brilliant Blue R (RBBR), and they showed about 75% decolorization rates during the 48 h reactions. Although the decolorization efficiency decreased by 10-15% after a repeated use of the immobilized enzymes, these can be reused in various degrading reactions.