• Archives of Pharmacal Research
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• v.13 no.3
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• pp.265-268
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• 1990

The effects of lignans, related to macelignan, on hepatic microsomal drug-metabolizing enzyme (DME) activity were evaluated to elucidate the structure-activity relationship in mice and rats. The compounds carrying the methylenedioxyphenyl nucleus were found to be the msot potent among compounds tested; which not only produced a marked inhibition of DME with a single dose but a significant induction with repeated treatments. Lack of the methylenedioxy group caused marked decrease in the activity, implying that a methylenedioxy group is essential and of major importance eliciting DME modifying activity.

• Archives of Pharmacal Research
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• v.14 no.4
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• pp.330-335
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• 1991

The effects of physostigmine and neostigmine on the parathin induced toxicity were examined in adult female rats. Physostigmine $(100\;{\mu}g/kg,\;ip)$ or neostigmine $(200\;{\mu}g/kg,\;ip)$ inhibited acetylcholinesterase (AChE) and cholinesterase (ChE) activities in blood, brain and lung when the enzyme activity was measured 30 min after the treatment. At the doses of two carbamates equipotent on brain AChE, neostigmine showed greater inhibition on peripheral AChE/ChE. The enzyme activity returned to normal in 120 min following the carbamates except in the lung of rats treated with neostigmine. Carbamates administered 30 min prior to parathion (2 mg/kg) antagonized the inhibition of AChE/ChE by parathion when the enzyme activity was measured 2 hr following parathion. Neostigmine showed greater protective effect on peripheral AChE/ChE. The effect of either carbamate on AChE/ChE was not significant 2 hr beyond the parathion treatment. Carbamates decreased the mortality of rats challenged with a lethal dose of parathion (4 mg/kg, ip) either when treated alone or in combination with atropine (10 mg/kg, ip). Lethal action of paraoxon (1.5 mg/ks ip), the active metabolite of parathion was also decreased by the carbamate treatment indicating that the protection was not mediated by competitive inhibition of metabolic conversion of parathion to paraoxon. The results suggest that carbamylation of the active sites may not be the sole underlying mechanism of protection provided by the carbamates.

• Journal of Plant Biology
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• v.33 no.4
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• pp.293-301
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• 1990

We have purified and characterized a deoxyribonuclease from zygotes of the eukaryotic green alga, Chlamydomonas reinhardtii and investigated effects of the polyamines, putrescine, spermidine and spermine on the purifed endonuclease-catalyzed cleavage of plasmid DNA. The enzyme has a molecular weight of about 37 kDa as measured by gel filtration and SDS-polyacrylamide gel electrophoresis. There is no requirement for a divalent cation. The activity is sensitive to ionic strength, as NaCl and KCl result in inhibition. The cleavage of plasmid DNA by the purified endonuclease was effectively inhibited by polyamines. The enzyme activity was inhibited more effectively by spermine than by spermidine. The inhibition by putrescine was lower than the other two polyamines.

• Preventive Nutrition and Food Science
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• v.20 no.3
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• pp.176-182
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• 2015

Abalone protein was hydrolyzed by enzymatic hydrolysis and the optimal enzyme/substrate (E/S) ratios were determined. Abalone protein hydrolysates (APH) produced by Protamex at E/S ratio of 1:100 showed angiotensin I converting enzyme inhibitory activity with $IC_{50}$ of 0.46 mg/mL, and APH obtained by Flavourzyme at E/S ratio of 1:100 possessed the oxygen radical absorbance capacity value of $457.6{\mu}M$ trolox equivalent/mg sample. Flavourzyme abalone protein hydrolysates (FAPH) also exhibited $H_2O_2$ scavenging activity with $IC_{50}$ of 0.48 mg/mL and $Fe^{2+}$+ chelating activity with $IC_{50}$ of 2.26 mg/mL as well as high reducing power. FAPH significantly (P<0.05) protected $H_2O_2$-induced hepatic cell damage in cultured hepatocytes, and the cell viability was restored to 90.27% in the presence of FAPH. FAPH exhibited 46.20% intracellular ROS scavenging activity and 57.89% lipid peroxidation inhibition activity in cultured hepatocytes. Overall, APH may be useful as an ingredient for functional foods.

• Applied Microscopy
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• v.17 no.2
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• pp.55-71
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• 1987

To investigate the effects of lead on the electron transport system and ultrastructure of mouse kidney mitochondria, various lead acetate concentrations were treated in vitro and respiration rate, enzyme activities were measured. Ultrastructural changes at state IV respiration were also observed. To compare with in vivo experiments, mouse were injected intraperitoneally of 100 mg lead acetate per kg body weight and state IV respiration rate and enzyme activities were measured. Ultrastructure of renal proximal tubular cells were also observed. In in vitro treatement, decreased state IV respiration, decreased enzyme activities, ruptured membranes and inhibition of condensed to orthodox transformation were observed. In in vivo treatment, decreased state IV respiration and decreased enzyme activities were observed after 24 hrs of i.p. injection. Cytochrome c oxidase activity showed twice the inhibition compared to NADH-CoQ reductase activity at 24 hrs. Continuous decreased state IV respiration was observed after 48 and 72 hrs of injection, however, the enzyme activities were increased to control level. Lead-protein complex which probably inhibits the toxic effects of lead appeared. To conclude, dominant effect of lead on the electron transport system appeared at cytochrome c oxidase activity, and the increased enzyme activities may be a result of appearance of lead-protein complex.

• BMB Reports
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• v.28 no.2
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• pp.100-106
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• 1995

S-adenosylmethionine (SAM) synthetase was purified to homogeneity from soybean (Glycine max) axes. The enzyme was purified 216-fold with a 1.5% yield by ammonium sulfate fractionation, acetone fractionation, ion exchange chromatography with DEAE-sephacel, gel filtration with Sephacryl S-300, and afffinity chromatography with ATP-agarose. The enzyme activity reached a maximum 3 days after germination. SAM synthetase had a subunit molecular weight of 57,000 daltons from a silver stained single band on SDS-PAGE. The molecular weight of the enzyme was 110,000 daltons from Sephacryl S-300 gel filtration. The enzyme was composed of two identical subunits. The $K_m$ values of the enzyme for L-methionine and ATP were 1.81 and 1.53 mM, respectively. The enzymatic activity was not affected by polyamines, agmatine, or SAM analogues, but was inhibited by SAM. The inhibition pattern was showed non-competitive for L-methionine and uncompetitive for ATP. The activity of SAM synthetase was inhibited by thiol-blocking reagents. The enzyme was induced by treatment with $10^{-3}$ M putrescine at germination. Experimental data revealed a possible novel regulation mechanism of polyamine biosynthesis through several endogenous intermediates.

• Korean Journal of Veterinary Research
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• v.23 no.1
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• pp.9-16
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• 1983

The effects of ethanol on Na-K-ATPase activity were investigated with cat kidney homogenate. The results were summarized as follows: 1. Na-K-ATPase activity was inhibited with dose-dependent manner by ethanol of higher concentration than 1%, and showed an estimated $I_{50}$ (the inhibitor concentration to cause 50% inhibition) of 7.5%. 2. Hydrolysis of ATP was linear with the incubation time in the absence and presence of 8% ethanol, whereas it was different with preincubation time in the presence of 15% ethanol. 3. Inhibition of Na-K-ATPase activity by ethanol was not affected by increased enzyme concentration, and showed the reversibility of the inhibitory pattern. 4. Kinetic studies of cationic-substrate activation of Na-K-ATPase showed that ethanol had both properties of classical competitive inhibition for $Mg^{{+}{+}}$ or $K^+ and non-competitive inhibition for ATP or $Na^+$. 5. Arrhenius plot yield two break point at $21^{\circ}$ and $30^{\circ}C$ in the absence of ethanol, whereas showing only one break point at $18^{\circ}C$ in the presence of 8% ethanol. These results suggested that ethanol inhibited Na-K-ATPase activity reversible through a disturbance of microenvironment of lipids associated with the enzyme.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.196-196
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• 1998

Nitric oxide is involved in various physiological processes. Among isoforms of nitric oxide synthase, iNOS is partly responsible for inflammation and septic shock. During our continual search for anti-inflammatory flavonoids, we have found that flavonoids, especially flavones, possessed the inihibitory activity of NO production by iNOS from LPS-activated RAW 264.7 cell. In this study, flavonoids from Scutellaria radix were investigated for their inhibitory activity of nitric oxide production. It was found that wogonin, among tested flavonoids including baicalein, oroxylin A, skullcapflavone II, showed the strongest inhibition of nitric oxide production (IC$\sub$50/ = 17 uM). And this inhibition was, at least partly, due to down-regulation of iNOS enzyme induction, not due to direct inhibition of iNOS enzyme activity.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.57-58
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• 2000

Production of dye-decolorizing enzyme was investigated with the cultivation of Geotrichum candidum Dec1 (abbreviated to Dec1) using molasses as a cheap raw materials. Molasses was found to stimulate the enzyme production as well as a role of carbon source, because the production increased with molasses content up to 50 g/L. However, the severe inhibition of dye-decolorizing enzyme activity was observed even at low concentration of molasses 10 g/L when purified decolorizing peroxidase was used. Its inhibitory effect was reduced through the cultivation of Dec1. The fractions of molasses separated by a gel chromatography showed the different degrees of inhibition. As a way to reduce the inhibitory effect, the dilution of culture broth was examined, and the total decolorizing activity for Reactive blue 5 increased 7 times as much as that of original culture broth by 30 times dilution. On the basis of result, we proposed a process scheme which can fully utilize both positive and negative effect of molasses in dye-decolorizing process using molasses.

• 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.