• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.1022-1030
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• 2004

The gene encoding Aquifex pyrophilus (Apy) DNA polymerase was cloned and sequenced. The Apy DNA polymerase gene consists of 1,725 bp coding for a protein with 574 amino acid residues. The deduced amino acid sequence of Apy DNA. polymerase showed a high sequence homology to Escherichia coli DNA polymerase I-like DNA polymerases. It was deduced by amino acid sequence alignment that Apy DNA polymerase, like the Klenow fragment, has only the two domains, the $3'{\rightarrow}5'$ exonuclease domain and the $5'{\rightarrow}3'$ polymerase domain, containing the characteristic motifs. The Apy DNA polymerase gene was expressed under the control of T7lac promoter on the expression vector pET-22b(+) in E. coli. The expressed enzyme was purified by heat treatment, and Cibacron blue 3GA and $UNO^{TM}$ Q column chromatographies. The optimum pH of the purified enzyme was 7.5, and the optimal concentrations of KCl and $Mg^{2+}$ were 20 mM and 3 mM, respectively. Apy DNA polymerase contained a double strand-dependent $3'{\rightarrow}5'$ proofreading exonuclease activity, but lacked any detectable $5'{\rightarrow}3'$ exonuclease activity, which is consistent with its amino acid sequence. The somewhat lower thermostability of Apy DNA polymerase than the growth temperature of A. pyrophilus was analyzed by the comparison of amino acid composition and pressure effect.

• Parasites, Hosts and Diseases
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• v.41 no.3
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• pp.165-169
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• 2003

This study describes the characterization of 80 kDa pretense showing gelationlytic property among three pretenses in the excretory/secretory proteins (ESP) from Toxoplasma gondii. The pretense activity was detected in the ESP but not in the somatic extract of RH tachyzoites. This pretense was active only in the presence of calcium ion but not other divalent cationic ions such as $Cu^{2+},{\;}Zn^{2+},{\;}Mg^{2+},{\;}and{\;}$Mn^{2+}$, implying that $Ca^{2+}$ is critical factor for the activation of the protease. The 80 kDa pretense was optimally active at pH 7.5. Its gelatinolytic activity was maximal at $37^{\circ}C$, and significant level of enzyme activity of the pretense remained after heat treatment at $56^{\circ}C$ for 30 min or $100^{\circ}C$ for 10 min, This thermostable enzyme was strongly inhibited by metal chelators, i.e., EDTA, EGTA, and 11 10-phenanthroline. Thus, the 80 kDa pretense in the ESP secreted by T. gondii was classified as a calcium dependent neutral metalloprotease.

• Journal of Life Science
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• v.11 no.6
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• pp.574-581
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• 2001

This study was performed to evaluate the inhibition effects of fermented soybean on lipid perosidation and antioxidative relative enzyme activity. in vivo. Fermented soybean was induced the high SOD activity, while significantly inhibited on the peroxide value of linoleic acid and lipid perxidation from rat microsome induced by Fe$^{2+}$ ascorbate system, Sprague-Dawley(SD) male rats were fed basic diet, and experimental diets group added 200 or 500 mg/kg fermented soybean for 2 weeks. The effect of fermented soybean is also significantly increased catalase and glutathione peroxidase activities, while significantly inhibited the lipid peroxidation of rat liver microsome in a dose dependent manner. Therefore, these results suggest that fermented soybean has antioxidative activity which is related enzyme to prevention of oxidative stress.s.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.675-679
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• 2006

The effect of water extract from Thesium chinese Turczaninow (TCTW) on proliferation of human breast cancer cells, nitric oxide production, nitric oxide synthase expression, and ornithine decarboxylase activity was tested. TCTW inhibited the growth of both estrogen-independent MDA-MB-231 and estrogen-dependent MCF-7 human breast cancer cells. Lipopolysaccharide-induced nitric oxide (NO) production was significantly reduced by TCTW at the concentrations of 1.0 (p<0.05) and 5.0 mg/ml (p<0.005). Expression of inducible nitric oxide synthase (iNOS) was also suppressed with the treatment of TCTW in Western blot analysis. TCTW inhibited induction of ornithine decarboxylase by 12-O-tetradecanoylphorbol-13-acetate (TPA), a key enzyme of polyamine biosynthesis, which is enhanced in tumor promotion. Therefore, TCTW is worth further investigation with respect to breast cancer chernoprevention or therapy.

• Mycobiology
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• v.37 no.2
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• pp.128-132
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• 2009

The antitumor effects of Phellinus linteus extract (Keumsa Linteusan) were investigated in a CT-26 cell-injected colon cancer mouse model. When administered orally (250${\sim}$1,000 mg/kg body weight), Keumsa Linteusan significantly inhibited the growth of solid colon cancer. The highest dose was highly effective, reducing tumor formation by 26% compared with the control group. The anticomplementary activity of Keumsa Linteusan increased in a dose-dependent manner. Lysosomal enzyme activity of macrophages was increased by 2-fold (100 ${\mu}$/ml) compared with the control group. Keumsa Linteusan can be regarded as a potent enhancer of the innate immune response, and can be considered as a very promising candidate for antitumor action.

• 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 PSK Conference
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• 2003.10b
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• pp.202.4-203
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• 2003

The present study was carried out to clarify whether isoflavonoids isolated from Belamcandae Rhizoma (Iridaceae) inhibit inflammation and angiogenesis by the experimental methods in vitro and in vivo. Among the isolated isoflavonoids, such as irigenin, irisflorentine, and iristectorene B inhibited nitric oxide (NO) production, as measured by nitrite formation at 3-30 ${\mu}M$. Also these compounds reduced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) enzyme expression in a concentration dependent manner, when measured by western blotting, at 3-30 ${\mu}M$. Irigenin, irisflorentine and iristectoren B decreased angiogenesis of chick embryos in the chorioallantoic membrane assay. These compounds also reduced the proliferation of calf pulmonary arterial endothelial (CPAE) cells and found to possess relatively weak gelatinase/collagenase inhibitory activity in vitro. These compounds, when administered subcataneously at the dose of 30mg/kg for 20 days to mice implanted with murine Lewis lung carcinoma (LLC), caused a significant inhibition of tumor volume. Therefore, antiangiogenic activities of isoflavonoids from Belamcandae Rhizoma might be due to antiproliferative activities under inhibition the induction of COX-2 and iNOS enzyme.

• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.337-342
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• 1994

It is well known that angiotensin converting enzyme inhibitors(ACEIs) increase endothelium-dependent relaxation in aortic strips of spontaneously hypertensive rats(SHR) and this increase in relaxation may be due to altered endothelial nitric oxide breakdown. But there are few studies on the effect of the angiotensin II receptor blocker on the nitric oxide-mediated relaxation. So we attempted to investigate the effect of angiotensin II receptor blocker on the nitric oxide-dependent relaxation in isolated aorta of SHR. Two week-treatment of losartan (30 mg/kg/day) increased the acetylcholine$(10^{-9}\;to\;10^{-5}\;M)$-and histamine$(10^{-8}\;to\;10^{-4}\;M)$-induced relaxation in endothelium intact strips but 90 minutes-treatment of losartan $(10^{-4}\;M)$ showed no increase in relaxation. The phenylephrine $(10^{-7}\;M)$-induced contraction, repeated every 2 hours, was diminished gradually following lipopolysaccharide (LPS)-treatment $(100\;{\mu}g/ml)$ but there was no significant difference in enalapril- and losartan-treated group compared with control group. These results suggest that activity of the endothelial constitutive NO synthase may be changed by chronic treatment of angiotensin II receptor blockers and ACEIs but angiotensin II antagonist and ACEI have no effect on the inducible NO synthase activity in the isolated aorta of SHR

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.680-684
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• 2006

This study was designed to investigate effects of KH-304 in improving erectile dysfunction (ED), particularly in terms of nitric oxide (NO)-cGMP pathways. After oral administration of the KH-304 water extract, 1OOmg, 300mg, 500mg or 700mg per 1 kg of Dody weigh for 10days, We examined the expression and activity of two enzyme: neuronal NO synthase (nNOS), endothelial NO synthase (eNOS) and that act upon the major NO-cGMP signaling pathway in penile tissue. Effect of KH-304 on COMP degradation was also examined using bovine vascular smooth muscle cells pretreated with an NO donor, S-nitroso-N-Acetylpenicillamine (SNAP), Also, it examined the endothelial NO synthase (eNOS) for seaching effecting period (100mg, 300mg/kg for 10 and 30days) and peak intracavernous pressures (ICPS) in penile tissues rabbit copus cavernosum contracted by 10-6 M phenylephrine. The severely reduced peak intracavernous pressures (ICPS) in penile tissues were restored completely after KH-304 treatment, and KH-304 treatment significantly made the latency period earlier. Furthermore, the penile expression levels of nNOS, eNOS dependent NOS activities and COMP concentrations were increased significantly in the KH-304 100, 300mg treated rats. These results suggest that KH-304 with high expression of NOS may be useful in erectile dysfunction.

• Nutritional Sciences
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• v.8 no.4
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• pp.226-230
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• 2005

To keep blood glucose levels as close to normal as possible is the major goal of diabetes mellitus treatment $\alpha$-Glucosidase is the enzyme that digests die1my carbohydrate and inhibition of this enzyme may suppress postprandial hyperglycemia. The methanol extract of Polygonum multiflorum Thunberg was tested for inhibitoty activity against $\alpha$-glucosidase in vitro and in vivo. Polygonum multiflorum Thunberg extract inhibited yeast $\alpha$-glucosidase activity in a concentration-dependent manner. Polygonum multiflorum Thunberg showed an $IC_{50}$ value of 0.48 mg/mL. The ability of Polygonum multiflorum Thunberg extract to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without the methanol extract of Polygonum multiflorum Thunberg extract (500 mg/kg) was administered to diabetic rats by gastric intubation after an overnight fast A single oral dose of Polygonum multiflorum Thunberg extract significantly inhibited increases in blood glucose levels at 60 and 90 min (p<0.05) and significantly decreased incremental response areas under the glycemic response curve (p<0.05). These results suggest that Polygonum multiflorum Thunberg may have an antihyperglycemic effect by inhibiting $\alpha$-glucosidase activity in the animal model of diabetes mellitus.