• Applied Biological Chemistry
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• v.14 no.2
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• pp.131-135
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• 1971

1. L-Tyrosine-${\alpha}$-ketoglutaric transaminase and p-hydroxyphenylpyruvic acid oxidase are distributed in Aspergillus oryzae. 2. L-Tyrosine oxidation in extracts of acetone powder, cell free extract and culture liquid of Aspergillus oryzae cultivated in the shaking culture are considerably accelerated by the addition of ${\alpha}$-ketoglutaric acid and then formation of glutamic acid was identified by chromatography method. 3. The roles of ${\alpha}$-ketoglutaric acid and pyridoxal phosphate have been shown to be an amino group acceptor in a transamination reaction. 4. Enzyme systems of an extracts of acetone powder and cell free extract also rapidly oxidized L-tyrosine and p-hydroxyphenlpyruvic acid to homogentisic acid. 5. The optimum pH for L-tyrosine-${\alpha}$-ketoglutaric acid transaminase was pH values of 6.0 and 6.5, and that for p-hydroxyphenylpyruvic acid oxidase was at pH values of 7.5.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.791-794
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• 1994

Sixteen kinds of naturally occurring phenolic compounds including 5 stilbenes, 7 flavonoids and 4 anthraquinones were examined in the inhibitory activity against rat liver AADC(aromatic L-amino acid decarboxylase) in vitro, using 5-hydroxytryptophan as a substrate. Three hydroxystilbenes, resveratrol 1, rhapontigenin 3 and piceatanol 5, which were known to be monoamine oxidase A inhibitors, exhibited a significant inhibition against AADC($IC_{50}$=20, 8 and $5\;{\mu}M$, respectively). By the comparison of the activity of each phenolic compound, it was suggested that the 3',4'-dihydroxyphenyl group of stilbenes or flavones was the best pharmacophore for the AADC inhibitory activity.

• KSBB Journal
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• v.14 no.3
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• pp.322-327
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• 1999

The cholesterol oxidase(EC.1.1.3.6) produced from Streptomyces sp. No.4 which isolated from soil was purified and investigated for the enzymatic properties. The enzyme was purified specifically by cholesterol affinity column chromatography with a yield of 28.3%. The purified enzyme showed a single polypeptide on SDS-PAGE and the molecular weight was estimated to be 60,000 daltons. The enzyme activity was strongly inhibited by metal ions such as $HgCl_2$ and $CuSO_4$. Dithiothreitol and mercaptoethanol inhibited the enzyme activity at concentration of 1mM. The Michaelis constant(Km) for cholesterol was found to be 1.38mM by Lineweaver-Burk plot analysis. Amino acid analysis showed that the enzyme protein was composed of 416 amino acid residues including 52moles of glycine and 19moles of tryptophane.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.65-71
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• 1996

Characterization of Polyphenol oxidase (PPO) in Perillae Folium, particullarly inhibitor studies were investigated. This enzyme was stable at pH 5.0 and the residual activity of PPO at ${\geq}$ ph 5.5 was estimated to be very low. PPO activity was decreased slightly by adding amino acid with catechol as a substrate, particullary PPO activity was inhibited markedly by cystein, histidine, lysine and arginine. In the absorption spectra of the product formed when catechol was oxidized by PPO, with a ${\lambda}_{max}$ at 410nm, the peak shifted toward ${\lambda}_{max}$ 520nm by addition of L-proline. At relatively low concentrations($10^{-3}M$), sulfite and dithiothreithol completely inhibited PPO activity. Inhibition of PPO activity by amino acids and inhibitors increased or decreased depending on the pH used to measure it.

• 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.

• YAKHAK HOEJI
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• v.35 no.3
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• pp.222-230
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• 1991

Polyphenol oxidase (PPO) was purified from an extract of Perillae Folium by ammonium sulfate fractionation and sephadex G-150 gel filtration, which molecular weight estimated 65,000$\pm$1,000 in SDS-gel electrophoresis, and pI value was 4.8. The pH and temperature optima were 6.0 and $30^{\circ}C$ respectively. $K_{m}$ values of the PPO for various phenolics derived from Lineweaver-Burk plots were 4.0$\times$10$^{-4}$, caffeic acid; 4.2$\times$10$^{-3}$M, 4-methylcatechol. The inhibition by 4-nitrocatechoi, potassium cyanide, cysteine, 2-mercaptoethanol was competitive with $K_{i}$ values of 7.6$\times$10$^{-5}$M, 7.2$\times$10$^{-5}$M, 3.6$\times$10$^{-5}$M, 2.2$\times$10$^{-5}$M, respectively. Among the divalent cations, Cu$^{2+}$ ion was strong activator on PPO and Zn$^{2+}$, Ni$^{2+}$ ions were little effect on PPO activity. In comparing the amino acid composition of Perillae Folium PPO with that of wheat isozyme, grape, spinach showed similarity. But the content of glycine phenylalanine was abundant relatively.

• The Korea Journal of Herbology
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• v.22 no.2
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• pp.51-63
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• 2007

Objectives : For the congenital feeble, the Gongjindan is useful medicine. The experiment is to estimate the value of the Gongjindan as therapeutic agent preventing against aging with an analysis of the ingredients and the bio-activating effects by enzymologic methods. Methods : General ingredients' of the Gongjindan's extract were analyzed first and the quantitative analysis of a reducing sugar, a soluble protein, an amino acid and minerals was made. The Gongjindan, which is extracted, concentrated, and freeze drying with water, ethanol and chloroform, have got applied for the experiment. The effects on electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, whitening effect have been investigated in the physiological activity measurement of function experiment. Results : The contained amino acid, in order of high amount, is Arginine, Alanine, Glutamic acid, Proline and the contained free amino acid is Glutamic acid, Leucine, Lysine, Phenylalanine. The derivative of free amino acid is ${\gamma}-Aminoisobutyric$ acid, Phosphoserine, Taurine. And the Gongjindan is containing 13 species of minerals in order of Ca>K>Na>Mg>Fe>AI>Mn. Then, to assure of the Gongjindan's capability of anti-oxidation, these following subjects-polyphenol, electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, tyrosinase inhibition- are analyzed and show high activity especially the most in ethanol extracts. Conclusion : With this analysis of ingredients, the Gongjindan is containing many materials functioning as anti-oxidation, anti-aging, anti-fatigue, neurotransmitter and immune agent. Moreover, In every water, ethanol, chloroform extracts, the Gongjindan's capability of anti-oxidation is confirmed so that we can apply to patients' treatment clinically.

• Journal of Aquaculture
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• v.3 no.2
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• pp.155-165
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• 1990

The albinic phenomenon of flat-fish (Paralichthys olivaceus) was investigated by measuring protein content, tyrosinase activity, amino acid composition, and contents of vitamin A and C. These materials in the flat-fish feed-stuff were also tested. The amount of skin protein was higher than that of muscle in normal flat-fish. Catechol and L-dopa oxidase activity did not differ between normal and albinic flat-fish. The free amino acid of skin in normal flat-fish was 7.5 times that in albinic one. Sulfur-containing amino acid in normal flat-fish was also 6.3 times that in albinic ones. Vitamin A was not detected in both of flat-fish. The content of vitamin C in normal flat-fish was 7.8 times that in albinic one. The contents of protein, sulfur-containing amino acid and vitamin C in micro-encapsulated feed (one commercial feed in Japan) were the highest among the feed-stuff used in this experiment. The melanin formation of flat-fish skin was affected by substrates such as aromatic amino acid and cofactor such as sulfur amino acid.

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.28.1-28.1
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• 2006

• BMB Reports
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• v.40 no.5
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• pp.697-707
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• 2007

Cytochrome $cbb_3$ oxidase is a member of the heme-copper oxidase superfamily that catalyses the reduction of molecular oxygen to the water and conserves the liberated energy in the form of a proton gradient. Comparison of the amino acid sequences of subunit I from different classes of heme-copper oxidases showed that transmembrane helix VIII and the loop between transmembrane helices IX and X contain five highly conserved polar residues; Ser333, Ser340, Thr350, Asn390 and Thr394. To determine the relationship between these conserved amino acids and the activity and assembly of the $cbb_3$ oxidase in Rhodobacter capsulatus, each of these five conserved amino acids was substituted for alanine by site-directed mutagenesis. The effects of these mutations on catalytic activity were determined using a NADI plate assay and by measurements of the rate of oxygen consumption. The consequence of these mutations for the structural integrity of the $cbb_3$ oxidase was determined by SDS-PAGE analysis of chromatophore membranes followed by TMBZ staining. The results indicate that the Asn390Ala mutation led to a complete loss of enzyme activity and that the Ser333Ala mutation decreased the activity significantly. The remaining mutants cause a partial loss of catalytic activity. All of the mutant enzymes, except Asn390Ala, were apparently correctly assembled and stable in the membrane of the R. capsulatus.