• Applied Microscopy
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• v.38 no.2
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• pp.125-133
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• 2008

Cytochrome-c-oxidase in mitochondria membrane is one of the most important factors for energy generation in the cell. As well as it is electron transfer enzyme, it is also heavily related to the apoptosis and other pathologic conditions. Meanwhile, porin is a protein located in inner and outer membranes of mitochondria, which is assumed to be functionally correlated with cytochrome-c-oxidase. It functions as forming electron transfer chain and conveying ATP. Therefore, using the immune-microscopy, It compared the distribution of cytochrome-c-oxidase and porin to figure out the formation and changes on cytochrome-c-oxidase in mitochondrial cristae. The sarcroplasm of cardic muscle tissue has many mitochondria. They are classified into two groups: the mitochondria with many cytochrome-c-oxidase and the mitochondria with only porins. The mitochondria with porins had few cytochrome-c-oxidases in their membrane; in contrast, the other mitochondria with rich cytochrome-c-oxidase had few porins in their walls. In addition, according to the location of the tissue in bovine heart, distribution of those kind of mitochondria had been clearly separated. As a result, it could be assumed that immature mitochondria has many porins to transfer the protein materials from sarcroplasm through the porins, and they made cytochrome-c-oxidase until it is enough, and then they decreased the porin and maintained minimum number of the porin.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.590-595
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• 1995

To examine the characteristics of antioxidative compounds from Capsella bursa-pastoris, ethanol extracts were separated into five organic solvent fractions; hexane(Fr.H), diethyl ether (Fr.E), ethyl acetate(Fr.EA), butanol (Fr.B), and water(Fr.D) fractions. Fr.B showed the greatest electron donating ability and inhibitory effect on lipid peroxidation. Whereas Fr.E had the most excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. The inhibitory effect of each fraction on xanthine oxidase was also measured. Fr.E had the strongest inhibitory effect on xanthine oxidase and $IC_{50}$ was $5.65\;{\mu}g$. The results indicate that the superoxide radical scavenging activity of Fr.E is caused by the inhibitory effect on radical generating system of xanthine oxidase. Also the order of inhibitory effect on xanthine oxidase was Fr.B

• Applied Biological Chemistry
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• v.21 no.2
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• pp.112-118
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• 1978

Xanthine oxidase from bovine thyroid glands was purified to apparent homogeneity when judged by analytical disc gel electrophoresis. The purification procedures include pancreatin digestion, butanol extraction, ammonium sulfate precipitation, calcium phosphate gel adsorption, ultrafiltration, calcium phosphate gel-cellulose column chromatography, gel filtration, preparative Sephadex G-25 column electrophoresis, and preparative polyacrylamide gel electrophoresis. The enzyme was enriched 1,000-fold. However, its specific activity was markedly low as compared with highly purified milk enzyme. Thyroidal xanthine oxidase exhibited a low specificity for substrates and electron acceptors. The kinetic properties of thyroid xanthine oxidase were found to be similar to those of the milk enzyme on the basis of Michaelis constants for common substrates.

• BMB Reports
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• v.28 no.3
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• pp.271-274
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• 1995

Glycolate oxidase is one of the key enzymes in the pathway of photorespiration. In this study we investigated the effects of light on the expression of the spinach glycolate oxidase gene. Continuous exposure to white light resulted in a gradual increase in the steady-state level of glycolate oxidase mRNA within a time period of 2~24 h in both etiolated and dark-adapted green seedlings. A short white light pulse also increased the level of glycolate oxidase mRNA in etiolated seedlings. The mRNA level reached a maximum at 6~8 h after the pulse and decreased by 24 h after the pulse. The induction patterns of the glycolate oxidase gene by white light appeared similar to those of the rbcS gene, indicating that a common or coordinating regulatory system may be involved in the expression of the glycolate oxidase and rbcS genes. A red light pulse induced an increase in the amount of glycolate oxidase mRNA and this effect was reversed by a subsequent far-red light pulse, suggesting that the expression of the glycolate oxidase gene is regulated by phytochrome.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.6
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• pp.520-525
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• 2000

Glucose oxidase was immobilized in polypyrrole by electrosynthesis. The enzyme had an influence on the redox properties of a complex enzyme electrode. In the cyclic voltammograms of the enazyme electrode new peaks were appeared at the potential around 0.7V vs. Ag/AgCl in additional to the typical peaks for polypyrrole. The more immobilized the stronger the peaks became. During the cycling the pH of electrolyte solution was decreased to about 4.4 The reason for that is to be the proton released from the carboxyl in the glucose oxidase in order to keep on a charge neutrality of the oxidized enzyme. This fact suggests that the new peaks in the voltammograms are caused by the redox of glucose oxidase. In the AC impedance spectrum analysis of the electrode the diffusion of electrolyte anion was limited because of chained structure of the enzyme. The faradic impedance was large since the glucose oxidase is an insulator. Therefore when glucose oxidase is entrapped the enzyme should be limited in amount. Because the growth of the polypyrrole is accompanied both charge transfer and mass transport. For the traditional electrosynthesis that means amount of enzyme present in the electrode is limited to as much as film growable.

• BMB Reports
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• v.29 no.4
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• pp.321-326
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• 1996

Spinach glycolate oxidase was subjected to a series of chemical modifications aimed at identifying amino acid residues essential for catalytic activity. The oxidase was reversibly inactivated by treatment with pyridoxal 5'-phosphate (PLP). The inactivation by PLP was accompanied by the appearance of an absorption peak of around 430 nm, which was shifted to 325 nm upon reduction with $NaBH_4$. After reduction, the PLP-treated oxidase showed a fluorescence spectrum with a maximum of around 395 nm by exciting at 325 nm. The substrate-competitive inhibitors oxalate and oxaloacetate provided protection against inactivation of the oxidase by PLP. These results suggest that PLP inactivates the enzyme by fonning a Schiff base with lysyl residue(s) at an active site of the oxidase. The enzyme was also inactivated by tryptophan-specific reagent N-bromosuccinimide (NBS). However, competitive inhibitors oxalate and oxaloacetate could not protect the oxidase significantly against inactivation of the enzyme by NBS. The results implicate that the inactivation of the oxidase by NBS is not directly related to modification of the tryptophanyl residue at an active site of the enzyme. Treatments of the oxidase with cysteine-specific reagents iodoacetate, silver nitrate, and 5,5'-dithiobis-2-nitrobenzoic acid did not affect significantly the activity of the enzyme.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.275-280
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• 2019

This study was performed to certify the inhibitory effect of aqueous extracts from sixty-seven medicinal plants on the activity of xanthine oxidase in vitro. Among the sixty-seven medicinal plants, Scutellaria baicalensis Georgi, Citrus aurantium L., Polygonum multiflorum Thunb., Pueraria thunbergiana (Sieb. et Zucc.) Benth., Citrus unshiu Marcor., Rubus coreanus Miquel, Camellia sinensis L., and Poncirus trifoliata Raf. were regarded as effective anti-gout sources. The active substances of P. multiflorum root extract were very stable at pH 2.0 and high temperatures. Xanthine oxidase activity was proportionally inhibited when concentrations of P. multiflorum extract increased. The aqueous extract from P. multiflorum root at a concentration of 2.0 mg/0.1 mL inhibited xanthine oxidase by 73.8%.

• Mycobiology
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• v.39 no.1
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• pp.64-66
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• 2011

Most fungi possess several hydrogen peroxide-generating enzymes, glucose oxidase and pyranose oxidase. Pyranose oxidase can use glucose as its substrate to generate hydrogen peroxide. White rot fungi, which degrade diverse recalcitrant compounds, contain lignin-degrading enzymes, and lignin peroxidase and manganese peroxidase require hydrogen peroxide for their enzymatic reactions. In this study, we isolated a cDNA fragment of pyranose oxidase from Phlebia tremellosa using PCR and examined its expression under the degradation conditions of diethylphthalate (DEP). Pyranose oxidase expression was enhanced up to 30% by the addition of DEP, and this result supports the possible involvement of pyranose oxidase in the degradation of recalcitrant compounds.

• Biomedical Science Letters
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• v.12 no.3
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• pp.185-190
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• 2006

Lysyl oxidase (LOX) catalyzes the lysine-derived cross-links of fibrillar collagens and elastin in the extracellular matrix. Recent molecular cloning has revealed existence of a LOX family consisting of LOX and four lysyl oxidase-like proteins (LOXL, LOXL2, LOXL3 and LOXL4). Pathological conditions associated with impaired LOX activity in several heritable and acquired disorders lead to severe structural and functional abnormalities of cardiovascular tissues, such as occlusion of coronary arteries and aneurysms, suggesting an essential role for the LOX family proteins in the maintenance of the cardiovascular system. However, the specific roles of the lysyl oxidase-like proteins in normal and pathological conditions of the cardiovascular tissues have not been established yet. Here, I report that LOXL3, a novel member of the LOX family, is predominantly expressed in the aorta, with an amine oxidase activity toward collagen and elastin, suggesting an essential role of LOXL3 in the development and maintenance of the aorta.

• The Korean Journal of Food And Nutrition
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• v.11 no.3
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• pp.354-358
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• 1998

The influence of hot water extracts and tannin obtained from persimmon leaves on xanthine oxidase were investigated. Above two samples had higher inhibitory effect against xanthine oxidase by hot water extracts and tannin obtained from persimmon leaves was 92.4% and 92.1% by addition of 2.0 mg/$m\ell$ of the hot water extracts and the tannin, respectively. The inhibitions by the hot water extracts and the tannin were of competitive mode with respect to xanthine as a substrate.