• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1889-1892
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• 2004

The peroxidase activity of cytochrome c was studied by using a chromogen, 2,2'-azinobis-(2-ethylbenzthiazoline-6-sulfonate) (ABTS). Initial rate of ABTS oxidation formation was linear with respect to the concentration of cytochrome c between 2.5-10 ${\mu}$M and $H_2O_2$ between 0.1-0.5 mM. The optimal pH for the peroxidase activity of cytochrome c was 7.0-8.5. The peroxidase activity retained about 40% of the maximum activity when exposed at 60 $^{\circ}C$. for 10 min. The peroxidase activity showed a typical Michaelis-Menten kinetics for $H_2O_2$ which Km value was 29.6 mM. Radical scavengers inhibited the peroxidase activity of cytochrome c. The peroxidase activity was significantly inhibited by the low concentration of iron chelator, deferoxamine. The results suggested that the peroxidase activity was associated with iron in the heme of cytochrome c.

• 한국식물병리학회지
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• 제1권3호
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• pp.178-183
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• 1985

수도품종 농백, 진흥, 낙동, 태백 등 4품종과 도열병균 KJ-101과 KJ-301의 2race를 사용하여 peroxidase 활성증가와 저항성과의 관계를 관찰하였다. peroxidase 활성은 수도유균가 성장할수록 모든 품종에서 증가되는 경향은 있었으나 품종간 차이는 크지 않았다. 도열병균을 접종 후 시간이 경과함에 따라 이병 잎에서는 무접종 건전잎보다 효소활성이 높았고 접종된 균주에 비친화적인 품종보다 발병이 심한 친화적 품종에서 더욱 높았다. 전기영동법에 의한 peroxidase pattern은 이병잎에서는 도열병균의 peroxidase band를 관찰할 수 없었다. 질소시비량을 증가시켰을 지라도 peroxidase 활성은 변함이 없었다.

• BMB Reports
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• 제43권3호
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• pp.170-175
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• 2010

Chaperone;Glutathione peroxidase;Peroxiredoxin;Schizosaccharomyces pombe;Thioredoxin peroxidase;To investigate the differences in the functional roles of peroxiredoxins (Prxs) and glutathione peroxidase (GPx) of Schizosaccharomyces pombe, we examined the peroxidase and molecular chaperone properties of the recombinant proteins. TPx (thioredoxin peroxidase) exhibited a capacity for peroxide reduction with the thioredoxin system. GPx also showed thioreoxin-dependent peroxidase activity rather than GPx activity. The peroxidase activity of BCP (bacterioferritin comigratory protein) was similar to that of TPx. However, peroxidase activity was not observed for PMP20 (peroxisomal membrane protein 20). TPx, PMP20, and GPx inhibited thermal aggregation of citrate synthase at 43$^{\circ}C$, but BCP failed to inhibit the aggregation. The chaperone activities of PMP20 and GPx were weaker than that of TPx. The peroxidase and chaperone properties of TPx, BCP, and GPx of the fission yeast are similar to those of Saccharomyces cerevisiae. The fission yeast PMP20 without thioredoxin-dependent peroxidase activity may act as a molecular chaperone.

• International Journal of Industrial Entomology and Biomaterials
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• 제12권1호
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• pp.21-28
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• 2006

Peroxidase activity was measured in brown leaf spot pathogen (Myrothecium roridum) inoculated potted mulberry (Morus alba) during pre-symptomatic to various symptom development stages and compared with corresponding healthy leaf tissues. The enzyme showed a pH optimum of 7.0 and the activity was linearly increased up to 15 min of incubation. The peroxidase had a broad substrate specificity and the rates of oxidation were in the rank of pyrogallol> guaiacol> ascorbate at pH 7.0. Catechol at 10 mM inhibited 89% of guaiacol-peroxidase and 76% pyrogallol-peroxidase activities, indicated higher non-specific peroxidation in pyrogallol dependent assay system in mulberry than guaiacol. The optimum requirement for the guaiacol dependent assay was 0.2 ml (${\approx}40-60{\mu}g$ equivalent of protein) of crude enzyme source. Excepting the 8th leaf from the apex, the peroxidase activity did not vary appreciably in different leaf positions. In pre-symptomatic phases, an initial (1 to 5 min) rise of peroxidase activity was noticed in inoculated leaves, and then maintained a plateau up to 300 min. In contrary, non-infected tissue showed a slightly increased trend of enzyme level up to 420 min. In infected tissue, a sharp transient increase (3.1 fold) of peroxidase activity appeared between 300 - 420 min post infections. Afterwards, significantly different but steady maintenance of enzyme levels were observed in two treatments. On the other hand, during symptom development, a sharp increase in peroxidase activity was noticed up to 4th grade of lesion appearance (25.1 % to 50% of leaf area infection), and then declined slightly. However, in non-infected but same age healthy leaves, such huge fluctuations of enzyme level did not apparent. A high positive correlation $(R^2=0.92)$ between peroxidase activity and leaf spot development grades was also marked. The result implies that pre-symptomatic burst (between 1 - 5 and 300 - 420 min) and subsequent increased trend of guaiacol peroxidase activity may require for the symptomatic manifestation of Myrothecium leaf spot in mulberry.

• 산업기술연구
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• 제21권A호
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• pp.343-349
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• 2001

This study characterizes the growth of white rot fungi Phanerochaete chrysosporium IFO 31249) and lignin peroxidase(LiP) activity in different submerged culture media. P. chrysosporium was grown in the form of pellet of various sizes from a spore inoculum under shaking liquid culture condition. While the growth of mycelia was higher under the nitrogen-sufficient culture than under the nitrogen-limited culture, ligninase activity was relatively lower. The lignin peroxidase appeared in nitrogen-limited culture and was suppressed by excess nitrogen. High level(40U/l) of lignin peroxidase activity was obtained in the growth medium containing 1.5mM veratryl alcohol, a secondary metabolite of P. chrysosporium. Lignin peroxidase production was not observed under conditions of nitrogen sufficiency or in balanced media, suggesting that control parameters could increase the activity by manipulating the secondary metabolism.

• Journal of Oral Medicine and Pain
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• 제33권1호
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• pp.1-8
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• 2008

타액에 존재하는 여러 항균물질은 상호작용을 통하여 부가적이거나 상승작용을 나타내고 때로는 저해작용을 나타내는 것으로 알려져 있다. 본 연구는 in vitro 상에서 lysozyme과 peroxidase 사이의 상호작용을 효소활성 측면에서 조사하고자 시행되었다. Lysozyme과 peroxidase의 상호작용은 hen egg-white lysozyme(HEWL)과 bovine lactoperoxidase(bLP)를 혼합하는 방법으로 조사되었고, peroxidase system이 lysozyme에 미치는 영향은 potassium thiocyanate와 hydrogen peroxide를 추가적으로 첨가하는 방법으로 조사되었다. Lysozyme 활성은 Micrococcus lysodeikticus 기질용액의 혼탁도 변화를 측정하는 방법으로 측정되었고, peroxidase 활성은 NbsSCN 법으로 측정되었다. Wilcoxon signed rank 법을 이용하여 lysozyme과 peroxidase 효소활성 변화를 대조군과 비교하였다. 생리적 농도범위에서 bLP는 HEWL의 효소활성을 증가시켰으며(P < 0.05), 그 효과는 bLP의 농도증가에 따라 영향을 받았다. 하지만 HEWL는 bLP의 효소활성에 영향을 주지 못하였다. Thiocyanate는 HEWL의 효소활성에 영향을 주지 못하였고, potassium thiocyanate와 hydrogen peroxide를 추가한 peroxidase system도 HEWL 효소활성의 추가적인 상승을 유도하지는 못하였으며, hydrogen peroxide의 농도변화도 영향을 미치지 못하였다. 본 연구의 결과는 타액 항균 물질을 포함하고 있는 구강건강용품이나 구강에서 lysozyme과 peroxidase의 상호작용을 이해하는데 필요한 중요한 정보를 제공해준다.

• 약학회지
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• 제43권3호
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• pp.334-341
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• 1999

Thyroid peroxidase is a biochemical target protein for the antithyroid drugs. Ethanol extracts from one hundred and thirty seven natural products were screened for the inhibition of thyroid peroxidase activity. Thyroid peroxidase was purified from porcine thyroids, and the inhibition of peroxidase activity was evaluated using guaiacol oxidation (C-C coupling) assay. Twenty one natural products expressed a remarkable inhibition (>50%) of peroxidase activity at $330{\mu\textrm{g}}$ solid weight/m. The 50% inhibitory concentration ($IC_{50}$) of 70% ethanol extract from six potent natural products ranged from 3.1 to $31.2{\;}{\mu\textrm{g}}$ solid weight/m, in contrast to the range ($0.33~0.54{\;}{\mu\textrm{g}}/ml$) of $IC_{50}$ values fro catechin and epigallocatechin gallate as positive controls. Noteworthy, the extract of Camellia taliensis showed irreversible inhibition of the enzyme. It is suggested that extract from some natural products such as Camellia taliensis, Rheum undulatum or Euphorbia perinensis, exhibiting a potent inhibition of peroxidase activity, may be developed as sources of potent antithyroid agents.

• Journal of Plant Biology
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• 제33권4호
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• pp.259-269
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• 1990

Changes of peroxidase activity, polyamine content and ethylene production during somatic embryogenesis in suspension-cultured carrot (Daucus carota L.) cells were investigated. As compared with nonembyrogenic cells and their medium, embryogenic cells and their medium were characterized by higher levels of peroxidase at all times of culture period. Peroxidase in embryogenic cells showed higher oxidation activity of IAA than in nonembryogenic cells at the torpedo stage, but the IAA oxidation activity of peroxidase released into embryogenic medium was lower than that of peroxidase released into nonembryogenic medium. Peroxidase patterns of embryogenic and nonembryogenic cells showed three cathodic bands, and one anodic band, while peroxidase patterns released into embryogenic and nonembryogenic media did not show any anodic bands and the isoelectric points of cathodic peroxidase were pH 7.7, 7.5 and 6.6. Compared with nonembryogenic cells, polyamine content in embryogenic cells was increased by 15% at the torpedo stage, but polyamine ratio was constant, and ethylene production was extremely low at all times of culture period. Therefore, it is suggested that the peroxidase in embryogenic cells is correlated with embryogenesis by regulating hormone ratios through IAA oxidation, while the peroxidase isozyme patterns may be used as a biochemical marker of embryogenesis. The increase of polyamine content and the decrease of ethylene production suggest an interaction between polyamine and ethlyene during embryogenesis.

• 대한수의학회지
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• 제34권3호
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• pp.465-470
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• 1994

This study was undertaken to measure the activity of myeloperoxidase and leukocyte peroxidase of hen. 70 hens were decapitated to observe the activity of enzymes according to ages. The activity of peroxidase by the Lowry's method with bovine serum albumin as standard. Gel filtration chromatography was carried out of sephacryl S-300 column. The results obtained were summarized as follows; 1. The mean of specific activity of myeloperoxidase and leukocyte peroxidase was 16.80(units/mg) and 15(units/mg), respectively. 2. The specific activity of myeloperoxidase in 35 days hen was significantly increased and showed almost the same level of activity to 350 days hen. 3. The specific activity of leukocyte peroxidase in 35 days hen was significantly increased and showed a little increased tendency from 210 days to 350 days hen. 4. On the sephacryl S-300 column chromatography, two separated peaks of myeloperoxidase activity were observed. The molecular weights of myeloperoxidase were 57,000 dalton and 13,700 dalton.

• 한국응용곤충학회지
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• 제17권4호
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• pp.193-199
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• 1978

옥수수 식물체에 녹병 (Puccinia sorghi)이 감염된 상태와 비감영상태하에서 Peroxidase(Px) activity(활동)를 좌우하는 견전인자의 행동을 규명하기 위해 5개의 선발된 자식계통과 이들사이에 가능한 10개의 $F_1$(잡종 제일세대)을 갖고 Px의 활동에 관한 유전분석 시험을 실시해 본 결과 다음의 결론을 얻었다. 1. 이용한 5개 자식계통과 10개의 $F_1$사이의 Px활동은 크게 달랐다. 2. 수개의 유전인자에 의해서 좌우되는 일반저항성정도 와 Px활동은 일치되지 않았다. 상가적 유전인자에 의해 좌우되는 높은 일반저항성 계통 CM105는 높은Px의 활동을 보였으나, 다른 저항성계통 Oh545는 낮은 Px의 활동을 보였다. 3. 녹병감염과 비감염상태하에서의 Px의 활동은 수병균접종후 2일때는 차이가 없었으나 접종후 8일때는 감염식물체에서 유의차를 보이는 높은 Px활동이 측정되었다. 4. 옥수수에 있어서 Px의 활동을 좌우하는 유전인자는 상가적작용을 주로 일으키는 GCA(일반조합능력)효과에 의하고, 비상가유전인자에 의한 SCA(특수조합능력)효과는 비교적 낮았다. 5. 우성 단인자 저항성에 의해서 좌우되는 특수저항성 유전인자 $R_{p1}^d$ 보유한 식물체는 저항성 유전인자를 보유하지 않는 이병성 식물체에 비해서 높은 Px의 활동을 보였다. 이는 12개의 밝혀진 Px중 주로 $Px_3$와 Px_7$의 증가에 기인한다. 6. 본 시험에서 얻어진 옥수수의 녹병저항성과 관련한 Px의 활동은 단 특수성저항성 유전인자인 경우에만 타 작물에서 얻은 시험결과와 유사한 점이 있다.