• Archives of Pharmacal Research
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• v.15 no.3
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• pp.215-219
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• 1992

S. fradiae exhibited the highest acetanilide p-hydroxylation activity among the Streptomyces spp. screened. Studies with inhibitors (metyrapone, 2. 6-dichloroindophenol, $\alpha,\alpha'$-dipyridyl, o-phenanthroline) and an absorption peak after CO treatment suggested that S. fradiae hydroxylase activity was due to cytochrome p-450. This hydroxylase activity was increased to ten times in the cell extract containing 0.5 mM sodium azide. Furthermore, the sedimentary activity in $105,000\times{g}$ centrifugal forces and solubilization of the activity with Triton-X 100 implied that this enzyme was membrane bound monooxygenase. pH Optimum of the enzyme was 6.5 in membrane bound state.

• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1057-1061
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• 2002

The Hafnia alvei aspartase activity with acetic anhydride treatment gradually increased and reached 7.5-fold that of the native one. The activity of the acetylated aspartase was a little higher than that of the native enzyme, indicating that the cooperativity between a substrate and enzyme is increased. The optimum temperature of the native asparatse was $45^{\circ}C$, and that of the acetylated enzyme shifted to $40^{\circ}C.$ The pH vs. the activity profile of the acetylated asparatse was also different from that of the native enzyme. The initial velocity pattern of the acetylated aspartase intersects to the left of the ordinate, indicating the sequential kinetic mechanism other than a rapid equilibrium ordered one. The reciprocal plots for aspartate of the native aspartase were curved, but those of the acetylated aspartase were linear, indicating the Michaelis-Menten kinetics. The helical content of the acetylated aspartase was rather decreased to $9{\textperthousand}$ than that $(63{\textperthousand})$ of the native one.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.1-8
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• 1987

An extracellular $\beta$-1, 3-glucanase from Pseudomonas stutzeri KF 13 was purified about 390 with 26% recovery. The purified enzyme revealed a single band by polyacrylamide gel electrophoresis and SDS-polyacrylamide gel electrophoresis. The enzyme was stable in a pH 6.0 to 9.0, and relatively thermostable. The optimal pH and temperature on the enzyme activity were found to be 5.8 and 45.deg.C, respectively. The activation energy was calculated to be 16,130 cal per mole. The Km value for laminarin was found to be 3ng per ml and the molecular weight was determined to be 28,000 by gel filtration and 26,000 daltons by SDS-acrylamide gel electrophoresis. The enzyme was inhibited by 1.0mM of $Hg^{2+}$, and strongly inhibited by 1.0mM of p-chloromercuribenzoic acid.

• The Korean Journal of Food And Nutrition
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• v.7 no.2
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• pp.119-123
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• 1994

Aspergillus sp. BY-54 which produced a strong dextran hydrolyzing enzyme was isolated from soil. Using this strain, the optimal cultural conditions, enzyme purification and characterization were studied. The results are as follows : The optimal concentration of dextran as carbon source was l%. and the optimum temperature and the initial pH for enzyme production was 3$0^{\circ}C$, and 7.0, respectively. Dextranase was purified by DEAE-cellulose column chromatography with a linear gradient increase in NaCl. Km value of dextranase was 0.222%, and several glucans containing various types of glucosidic linkages such as DEAE-sephadex, CM-sephadex and sephadex G-100 were almost digested to a large extent with this dextranase. The enzyme was strongly inhibited by sodium fluoride, KMnO4 and p-CMB, while KCN caused 20% of activation.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.96-106
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• 2001

The phase II detoxifying enzymes are inducible by a variety of compounds and play an essential role for the protection of cells. Many of chemoprotective agents trigger cellular signals for the phase II enzyme induction, which subsequently activate gene transcription through ARE activation.(omitted)

• IMMUNE NETWORK
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• v.12 no.6
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• pp.230-239
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• 2012

Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

• Journal of Life Science
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• v.8 no.6
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• pp.737-740
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• 1998

Effect of oral administration with fibrinolytic enzyme isolated from fermented anchovy(the traditional fermented food in Korea called Myulchi Jeot-gal) and its functionally active enzyme to rat, activation of plasma fibrinolysis was observed. The euglobulin fibrinolytic activities and the plasma levels of H-D-Val-Leu-Lys-pNA(S-2251) amidolysis reached a maximum at 3 hours after the administration to rat. And euglobulin Iysis time(ELT) value after oral admi-nistration showed its activity 2∼3 hours later. From the above result, it was confirmed the enzyme activity in blood by oral administration fibrinolytic enzyme through animal experiment.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.243-254
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• 1994

Inflammatory diseases, allergic and asthmatic disorders are caused by the mediator release from the activation of the phospholipase C (PLC), phospholipase D (PLD), methyltransferase or adenylate cyclase etc. during IgG or IgE cross-linking of high affinity receptors on mast cells or basophil surface. One important enzyme activated after IgG or IgE receptor cross-linking is PLD, the enzyme which converts phosphatidylcholine (PC) to phosphatidic acid (PA). Under the hypothesis that these may be some differences in mediator release according to the difference in PLD activity, we attempted to confirm the ginseng saponin effects on the PLD activity. We examined the PLD activity during the passively sensitized mast cell activation in the presence of single component of ginsenosides $(Rc,\;Rg_1,\;Rg_2,\;Rg_3)$. We also measured the amount of mediators (histamine and leukotrienes) released by stimulating with ovalbumin (OA) or calcium ionophore (CaI), Guinea Pig lung mast cells were purified using enzyme digestion, count current elutriation, and discontinuous Percoll density gradient. In purified mast cells prelabeled with $[^3H]$ arachidonic acid or $[^3H]$ palmitic acid, PLD activity was assessed more directly by the production of labeled PEt by PLD-mediated transphosphatidylation in the presence of ethanol. Histanine release was determined by Spectrophotofluorometry, and leukotrienes by radioimmunoassay. The PLD activity during the passively sensitized mast cell activation is increased up to $3{\sim}5times$. The PLD activity during the passively sensitized mast cell activation in the presence of all ginsenosides is decreased up to $4{\sim}11$ times. $Rg_l\;and\;Rg_2$ ginsenoside pretreatment decreased histamine and leukotrienes by 50% in the OA-induced or by 40% in the Cal-induced mast cell after passively sensitization. Rc pretreatment poorly decreased histamine but leukotrienes decreased by 70% in the OA-induced or by 35% in the Cal-induced mast cell. $Rg_3$ ginsenoside pretreatment increased histamine release without challenging OA or Cal but leukotrienes decreased. These observations indicate that single unit of ginsenosldes may be an important contributor to inhibit the release of histamine and leukotrienes in the guinea pig lung mast cells, that inhibits the PLD-mediated formation of DAG evoked by mast cell activation.

• Journal of Oriental Neuropsychiatry
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• v.11 no.2
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• pp.1-9
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• 2000

In previous studies, heat shock has been reported to induce the apoptosis or programmed cell death through the activation of caspase-3. 1 investigated the effect of juniper pure essential oil on the heat shock-induced apoptosis in human astrocyte cell line CCF-STTGI. Treatment of the astrocytes with heat shock markedly induced apoptotic cell death. However, pretreatment of the astrocytes with juniper oil ingibited the heat shock-induced apoptosis. To determine whether juniper inhibits the heat shock-induced activation of these apoptotic proteases, activation of CPP32 was assessed by Western blotting. Consistent with flow cytometry. DNA fragmentation and giemsa staining, heat shock-induced activation of CPP32 was blocked by juniper oil. Poly(ADP-ribose) polymerase (PARP), cysteine protease substrates were fragmented as a consequence of apoptosis by heat shock. Juniper oil inhibited the PARP fragmentation. This juniper oil also inhibited the heat shock-induced activation of caspase-3. These results suggest that juniper oil may modulate the apoptosis through the activation of the interleukin-1-converting enzyme-like protease.

• BMB Reports
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• v.40 no.3
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• pp.341-348
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• 2007

Herpesvirus saimiri (HVS), a member of the $\delta$-herpesvirus family, encodes an oncoprotein called Saimiri Transforming Protein (STP) which is required for lymphoma induction in non-human primates. Previous study has shown that STP-C, an oncoprotein of HVS, activates NF-$\kappa$B signaling pathway. However, the detailed mechanism of STP-Cmediated NF-$\kappa$B activation has not been reported yet. We first report that STP-C interacts with TRAF6 protein in vivo and in vitro and further investigation shows that $Glu_{12}$ residue of STP-C is critical for binding to TRAF6. Introduction of ubiquitin together with STP-C augments NF-$\kappa$B activity compared to that of STP-C expression alone. STP-C expression further induces ubiquitination of endogenous TRAF6. In addition, either a deubiquitination enzyme, CYLD or a dominant negative E2-conjugation enzyme reduced NF-$\kappa$B activity in spite of the presence of STP-C, supporting that the interaction between STP-C and TRAF6 induces ubiquitination of TRAF6. NF-$\kappa$B activation by STP-C through the ubiquitinated TRAF6 causes the increased production of IL-8, an inflammatory chemokine and the enhanced expression of costimulatory molecule ICAM, which might ultimately contribute cellular transformation by the exposure of HVS-infected cells with inflammatory microenvironment and chronic activation.