• Korean Journal of Microbiology
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• v.14 no.3
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• pp.128-128
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• 1976

19 pesticides including 12 insecticides, 2 herbicides and 5 fungicides have been tested for mutagenic activity in the Salmonella/microsome system. It was found that insecticides, DDVP, Trichlorfon, Sumithion, Naled, fungicide, TMTD and herbicide NIP induced base substitute mutation and herbicide MO frameshift mutation. Mutagenicity of Sumithion and NIP was appeared only after rat microsomal enzyme activation and that of TMTD was increased after the microsomal enzyme activation.

• Korean Journal of Microbiology
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• v.14 no.3
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• pp.123-134
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• 1976

19 pesticides including 12 insecticides, 2 herbicides and 5 fungicides have been tested for mutagenic activity in the Salmonella/microsome system. It was found that insecticides, DDVP, Trichlorfon, Sumithion, Naled, fungicide, TMTD and herbicide NIP induced base substitute mutation and herbicide MO frameshift mutation. Mutagenicity of Sumithion and NIP was appeared only after rat microsomal enzyme activation and that of TMTD was increased after the microsomal enzyme activation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.856-862
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• 1994

In salt-preserved foods of every kinds, it was examined the growth condition of halophilic bacteria that induced a change of colour, taste, nutritive substance, a production condition of enzyme and a character of crude enzyme. Used bacteria is H. halobium a kind of extremely halophilic bacteria, and the required of optimum culture needed a quite long time of crude enzyme production is 168 hours. Optimum pH is about 7-7.5, so the traditional food of such neutrality pH as soybean paste and soy sauce particularly come into trouble because the growth can flourish in neutrality or alkaliescence, and the crude enzyme also appeared that best activation between pH 6 and pH 8. The optimum temperature is about 37$^{\circ}C$, the optimum temperature of enzyme is about 40 $^{\circ}C$ and the temperature stability is settled for 15 minutes and it is completely inactivated at 10 minutes. In the influence of each metal ion, Fe++ and Mn++ a stimulated the growth of H.halobium and the activation of enzyme, Cu++ and Zn++ were identified that made the growth and the activation of enzyme inhibit.

• Biomolecules & Therapeutics
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• v.16 no.1
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• pp.1-8
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• 2008

Mitochondria are important sensor of apoptosis. $H_2O_2-induced$ cell death rate was enhanced by serum deprivation. In this study, we investigated whether serum deprivation using 0.5 or 3 % FBS induces apoptotic cell death through mitochondrial enzyme activation as compared to 10 % FBS. Apoptotic cell death was observed by chromosome condensation and the increase of sub-G0/G1 population. Serum deprivation reduced cell growth rate, which was confirmed by the decrease of S-phase population in cell cycle. Serum deprivation significantly increased caspase-9 activity and cytochrome c release from mitochondria into cytosol. Serum deprivation-induced mitochondrial changes were also indicated by the increase of ROS production and the activation of mitochondrial enzyme, succinate dehydrogenase. Mitochondrial enzyme activity increased by serum deprivation was reduced by the treatment with rotenone, mitochondrial electron transport inhibitor. In conclusion, serum deprivation induced mitochondrial apoptotic cell death through the elevation of mitochondrial changes such as ROS production, cytochrome c release and caspase-9 activation. It suggests that drug sensitivity could be enhanced by the increase of mitochondrial enzyme activity in serum-deprived condition.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.175-181
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• 1977

Lysosomal enzyme latency was demonstrated for hydrolases from porcine leukocyte by suspending sediment sfrom differential centrifugation in 0.125 to 0.250 M sucrose. Specific activities pH optima and activation energies were determined for hydrolases distributed in various sedimentation fractions and for enzymes solubilized by n-butyl alcohol extraction. Specific activities of the hydrolases revealed the heterogeneity of the Iysosomal fractions relative to enzyme content. pH optima identified the enzyme as acid hydrolases with optima for cathepsin D and aryl sulfatase also at pH 6.8. Activation energies of some hydrolases were low revealing that these enzymes could function efficiently during low temperature aging of meat.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1500-1506
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• 2011

Tyrosinase is a widespread enzyme with great promising capabilities. The Lineweaver-Burk plots of the catecholase reactions showed that the kinetics of mushroom tyrosinase (MT), activated by $Co^{2+}$ and $Zn^{2+}$ at different pHs (6, 7, 8 and 9) obeyed the non-essential activation mode. The binding of metal ions to the enzyme increases the maximum velocity of the enzyme due to an increase in the enzyme catalytic constant ($k_{cat}$). From the kinetic analysis, dissociation constants of the activator from the enzyme-metal ion complex ($K_a$) were obtained as $5{\times}10^4M^{-1}$ and $8.33{\times}10^3M^{-1}$ for $Co^{2+}$ and $Zn^{2+}$ at pH 9 and 6 respectively. The structural analysis of MT through circular dichroism (CD) and intensive fluorescence spectra revealed that the conformational stability of the enzyme in these pHs reaches its maximum value in the presence of each of the two metal ions.

• The Journal of Korean Physical Therapy
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• v.15 no.1
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• pp.26-37
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• 2003

This study was to investigate the effect of 10th weeks Exercise of Different Intensity on the activation of antioxidation enzyme and lipid peroxidation. 15 subjects were divided into the 65$\%$ running exercise(EG; 5), 85$\%$ running exercise(EG: 5), and the control(CG: 5) groups. The exercise group had 10 week of running exercise 4 times a week with ACSM(1995) protocol, 65$\%$ of HRmax from the beginning to 5th week, 85$\%$ of HRmax from 6th to 10th week. The subjects had 60 min exercise for each day. After extracting the blood sample, the activation of antioxidation enzyme and lipid peroxidation were compared between the groups. The one way ANOVA was conducted about pretest, 5th week, and 10th week of the subject data. The results obtained from this study were as follows; 1. The 65$\%$ exercise group showed the significantly greater increase in the activation of SOD after 10 weeks for the rest and all-out exercise. (p < .05). 2. The 65$\%$ exercise group displayed the significantly higher increase in the activation of CAT after 10th weeks for the rest exercise. (p < .05). 3. The 65$\%$ exercise group had the significantly greater decrease in the activation of MDA after 10 weeks for the all-out exercise. (p < .05).

• BMB Reports
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• v.31 no.3
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• pp.233-239
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• 1998

A GABA synthesizing enzyme, glutamate decarboxylase, has been purified from bovine brain by several chromatographic procedures. The preparation appeared homogeneous on SDS-PAGE. The enzyme is a homodimeric protein with a molecular mass of 120 kDa. The activation of glutamate decarboxylase by ginesenosides from Panax ginseng C.A. Meyer has been studied. Preincubation of the enzyme with total ginsenoside, $Rb_2$ and Rc ginsenosides, increased glutamate decarboxylase activities in a dose-dependent manner. There was a reproducible decrease in $K_m$, in addition to a increase in $V_{max}$, in response to increasing concentrations of the Rc ginsenoside fraction. Upon addition of the ginsenoside to the enzyme, a decrease in flurorescence intensity was discernible, together with an increase in emission anisotropy. Judging from the anisotropy values, the ginsenoside is rapidly trapped by the protein matrix. Total ginsenoside was administered to rats and the rat brains were removed for the measurement of the changes of GABA shunt regulating enzyme activities. Among the GABA shunt regulating enzymes, only the glutamate decarboxylase activities were increased after ginsenoside treatment. Therefore, it is suggested that the ginsenosides may elevate the GABA level in brain by activation of glutamate decarboxylase and the enzymatic activation might be due to the conformational change induced by binding of ginsenoside to the enzyme.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.758-762
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• 2007

A new alkyldithiocarbonate (xanthate), as sodium salts, C2H5OCS2Na, was synthesized by the reaction between CS2 with ethyl alcohol in the presence of NaOH. The new xanthate was characterized by 1H NMR, IR and elemental analysis. Then, the new synthesized compound was examined for functional study of cresolase activity of Mushroom Tyrosinase (MT) from a commercial source of Agricus bisporus in 10 mM phosphate buffer pH 6.8, at three temperatures of 10, 20 and 33℃ using UV spectrophotemetry. 4-[(4-methylphenyl)- azo]-phenol (MePAPh) was used as a synthetic substrate for the enzyme for cresolase reaction. The results show that ethyl xanthate can activate or inhibit the cresolase activity of mushroom tyrosinase depending to the concentration of ethyl xanthate. It was concluded that the enzyme has two distinct sites for ethyl xanthate. The first one is a high-affinity activation site and the other is a low-affinity inhibition site. Activation of the enzyme in the low concentration of ethyl xanthate arises from increasing the affinity of binding for the substrate as well as increasing the enzyme catalytic constant. The affinity of ligand binding in the activation site is decreased by increasing of the temperature, which is the opposite result for the inhibition site. Hence, the nature of the interaction of ethyl xanthate is different in two distinct sites. The binding process for cresolase inhibition is only entropy driven, meanwhile the binding process for cresolase activation is not only entropy driven but also enthalpy driven means that hydrophobic interaction is more important in the inhibition site.

• Animal Bioscience
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• v.36 no.2
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• pp.315-321
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• 2023

Objective: The study was conducted to investigate the dephosphorylation of Pseudomonas aeruginosa flagellin (PA FLA) by sweet potato purple acid phosphatase (PAP) and the effect of the enzyme on the flagellin-mediated inflammatory response in the A549 lung epithelial cell line. Methods: The activity of sweet potato PAP on PA FLA was assayed at different pH (4, 5.5, 7, and 7.5) and temperature (25℃, 37℃, and 55℃) conditions. The release of interleukin-8 (IL-8) and the activation of nuclear factor kappa- light-chain-enhancer of activated B cells (NF-κB) in A549 cells exposed to PA FLA treated with or without sweet potato PAP was measured using IL-8 and NF-κB ELISA kits, respectively. The activation of toll-like receptor 5 (TLR5) in TLR5-overexpressing HEK-293 cells exposed to PA FLA treated with or without sweet potato PAP was determined by the secreted alkaline phosphatase-based assay. Results: The dephosphorylation of PA FLA by sweet potato PAP was favorable at pH 4 and 5.5 and highest at 55℃. PA-FLA treated with the enzyme decreased IL-8 release from A549 cells to about 3.5-fold compared to intact PA FLA at 1,000 ng/mL of substrate. Moreover, PA-FLA dephosphorylated by the enzyme repressed the activation of NF-κB in the cells compared to intact PA FLA. The activation of TLR5 by PA-FLA was highest in TLR-overexpressing HEK293 cells at a substrate concentration of 5,000 ng/mL, whereas PA FLA treated with the enzyme strongly repressed the activation of TLR5. Conclusion: Sweet potato PAP has the potential to be a new alternative agent against the increased antibiotic resistance of P. aeruginosa and may be a new conceptual feed additive to control unwanted inflammatory responses caused by bacterial infections in animal husbandry.