• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.188-188
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• 1998

Extracts of 24 edible vegetables were tested concerning their action on in vitro inhibition on dopamine ${\beta}$-hydroxylase (DBH) and monoamine oxidase (MAO). All vegetables were purchased in Korean market and their common names were kept. Radish sprouts, ‘kkoch-na-mul’, ‘chong-gyong-chae’, ragwort, applemint showed strong DBH inhibitory effect when tyramine and crude bovine adrenal DBH were used as substrate and enzyme, respectively. ‘Cham-chwi’(Aster scaber), kale, ‘cham-na-mul’(Pimpinella brachycarpa), leek were found to have MAO-A inhibitory effect with serotonin and crude rat brain MAO-A. Lettuce, ‘chong-gyong-chae’, radish sprouts, beet leaves were found to have MAO-B inhibitory effect with benzyl amine and crude rat liver MAO-B.

• 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.

• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.167-175
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• 1996

This studies were conducted to select optimal enzyme that produced hydrolysate from soybean, and to evaluated functionality of hydrolysate. Soybean powder was suspended with water and hydrolyzed by seven commercial proteases. Hydrolysate produced with protease from Bacillus subtilis showed the highest inhibition effect on the activity of angiotension converting enzyme(ACE), and the condition of enzymatic hydrolysis was 5cA substrate concentration, 0. l% enzyme concentration, 4 hour hydrolysis time. Under above optimum condition, soybean was hydrolyzed with protease from Bacillus subtilis yielding a DH (degree of hydrolysis) of about 49%. Hyrophobicity of hydrolysate was not correlated with the inhibition effect on ACE activity. The functionality of hydrolysate was significantly influenced by pH. Solubility of hydrolysate at alkali solution was greater than that at acidic solution.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.693-697
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• 1998

The influence of flavonols from onion skin on xanthine oxidase was investigated. Methanol extract was showed 12.8% of yield, 661.3mg% of flavonoids contents and 88.7% of inhibitory effect on xanthine oxidase F1 and F2 fractions were obtained from the methanol extract by ODS and Sephadex LH-20 chromatography. F1 and F2 fractions flavonols(3-OH free) identified by UV/visible spectroscopy. Inhibitory effect of F1 and F2 on xanthine oxidase were increased with increasing concentration. IC50s of F1 and F2 were 0.95$\mu\textrm{g}$ and 0.67$\mu\textrm{g}$, respectively. To confirm the specificity of F1 and F2 against xanthine oxidase, albumin was added to the reaction mixture. The inhibition of F1 and F2 may be due to specific binding to xanthine oxidase. The modes of their inhibitions were of mixed type with respect to xanthine as a substrate.

• Bulletin of the Korean Chemical Society
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• v.22 no.3
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• pp.288-292
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• 2001

The kinetic mechanism of Hafnia alvei aspartase in the amination direction has been determined in the absence of metal. The initial velocity pattern obtained by varying the concentration of fumarate at several fixed concentrations of NH4+ , shows an intersection on the left of the ordinate at pH 7.0, indicating that the kinetic mechanism is a sequential mechanism in which substrate inhibition by fumarate is observed. The dead-end inhibition pattern by varying the concentration of NH4+ at several fixed concentration of succinate shows an intersection on the left of the ordinate. These data are consistent with random addition of NH4+, or fumarate. The Haldane relationship gives a Keq of 1.18 ${\times}$10-3 M at pH 7.0, which is in agreement with the values obtained from the direct determination of reaction concentrations at equilibrium (6.0 $\pm0.2$ ${\times}$10-3 M).

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.208.2-208
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• 1978

Rice Straw was delignified by autoclaving with 1％ NaOH solution at $121^{\circ}C$ for one hour and was disintegrated by a Wiley mill to 60 mesh. This substrate was saccharified with cellulase produced by Trichoderma viride T04 in solid culture me-dium. The rate and extent of hydrolysis were both increased when high enzyme concentration and low substrate concentration were employed. The original cellulose was treated with 0.19 FPA unit for three hours and followed by the second treatment for the same period with the same concentration of enzyme after washing. By doing this the hydrolysis rate at the second stage could increase four folds of that unwashed. The same experiment with 0.32 FPA unit yielded two folds suggesting an end-product inhibition on the recaction system. The extent of hydrolysis however, could not be in-creased by this process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.57-61
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• 1983

The present study was undertaken to elucidate the effect of Serotonin and Norepinephrine on Aldehyde Oxidase activity in rabbit liver, in vitro. The results were as follows; 1. Aldehyde Oxidase was measured optimum substrate concentration at $5{\times}10^{-4}M$ and incubation time for 10 minutes. 2. Aldehyde Oxidase were inhibited by Serotonin and Norepinephrine. 3. It was observed that relationship between biogenic amines and substrate were competitive inhibition on Aldehyde Oxidase.

• Korean Journal of Pharmacognosy
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• v.37 no.4 s.147
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• pp.320-323
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• 2006

The effects of evodiamine on monoamine oxidase (MAO) activity were investigated. MAO was purified from mouse brain and the $K_m\;and\;V_{max}$ values of MAO were $78.5{\pm}5.28{\mu}M$ and $0.68{\pm}0.07$ nmol/min/mg protein, respectively (n=4). Evodiamine at $30-120{\mu}M$ showed an inhibitory effect on MAO activity using a substrate kynuramine with an $IC_{50}$ value of $104.2{\mu}M$ (n=4). Evodiamine also exhibited a non-competitive inhibition on MAO. The $K_i$ value for evodiamine was $72.5{\pm}10.8{\mu}M$ (n=4). These results suggest that evodiamine partially contributes to the regulation of monoamine content.

• Microbiology and Biotechnology Letters
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• v.10 no.4
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• pp.283-288
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• 1982

Trypsin inhibitor produced by Streptomyces sp. was investigated its reactive characteristics against trypsin. The mode of inhibition against trypsin was mixed type of non-competitive and competitive with casein, and enzyme-inhibitor complex was formed rapidly. The inhibitory activity was increased by the addition of isoleucine and depressed by silver, mercuric or cupric ion. And when egg albumin or hemoglobin was used as substrate for trypsin, the inhibition ratio was changed. The inhibitor inhibited coagulation of blood of bovine.

• The Korean Journal of Physiology
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• v.25 no.2
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• pp.179-188
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• 1991

Effect of a sulfhydryl reagent, p-chloromercuribenzoic acid (PCMB), on the transport of succinate was studied in brush border (BBMV) and basolateral (BLMV) membrane vesicles isolated from rabbit renal cortex. PCMB induced an irreversible inhibition of the $Na^+-dependent$ succinate uptake in a dose-dependent manner with $IC_{50}$ of 55 and $65\;{\mu}M$ in BBMV and BLMV, respectively. The inhibitory effect of PCMB was prevented by a pretreatment of vesicles with dithiothreitol. PCMB did not increase $Na^+$ permeability at concentrations inhibiting succinate uptake. The PCMB inhibition of succinate uptake was due to a change in Vmax, but not in Km. When membrane vesicles were pretreated with PCMB in the presence of unlabelled succinate, the inhibitory effect was significantly reduced. In both BBMV and BLMV, succinate uptake was inhibited by various sulfhydryl reagents with the inhibitory potency of following order: $HgCl_2$>DTNB>PCMBS>PCMB. These results suggest that sulfhydryl groups are essential for dicarboxylate transport and that they may be located at or near substrate binding sites of the transporters in renal brush border and basolateral membranes.