• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1505-1511
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• 2004

Inhibition of angiotensin converting enzyme (ACE) activity is one of the common antihypertensive methods functioned by drugs such as captopril, lisinopril and enalapril to serve as inhibitors of ACE. This study was designed to compare the effects of enalapril, an angiotensin-converting enzyme inhibitor and GLM002, an oriental medicine, on tail systolic pressure, aorta and plasma properties in spontaneously hypertensive rats (SHR) after 4 weeks of treatment. During the treatment, blood pressure was depressed to normal in GLM002 and enalapril groups. The treatments of enalapril and GLM002 were discontinued in 4 weeks. One week after the treatment stop, systolic blood pressure was smoothly increased in both groups; the increment of blood pressure was slightly greater in GLM002-SHR, but the increment of plasma ACE activity was proportionately similar in each group. In the aspects of the triglyceride, HDL and total cholesterol level, those levels were slightly different among each group. We also conducted clinical dosage of GLM002 to the patients who have mild and severe hypertension for approximately 7 weeks. Clinical treatments also showed remarkable efficiencies on blood pressure (systolic blood pressure, diastolic blood pressure), complete blood count (CBC) routine, differ count (NEUTRO, LYM, MONO, EOS and BASO) and R-chemistry. We conclude that GLM002, like already proven enalapril, plays a role as an angiotensin-converting enzyme inhibitor, and can be suggested as a drug candidate for curing hypertension.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.150-155
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• 1992

- Some properties of an extracellular cytosine deaminase excreted from an isolate from soil samples were examined after 20~80%' ammonium sulfate fractionation. The enzyme catalyzed the conversion of cytosine and 5-fluorocytosine into uracil and 5-fluorouracil by substrate specificity, respectively. The optimum temperature and storage time on the stability of the enzvme preparation were below $50^{\circ}C$ keeping above 90% of the residual activity and near 4 days keeping above 80% of the residual one in Tris-HCI buffer. The maximum activity was also obtained at 8.0 in pH and 37'C in temperature. The pHs and temperatures for enzyme activity ranged from 8.0~8.5 and from 37~$45^{\circ}C$. respectively. The presence of $Ag^-,Hg^{2-}, Zn^{2-}, Cu^{2-}, Sn^{2-}, \; or\; Pb^{2-}$ in the reaction mixture resulted in the marked inhibition in enzyme activity, but 1 mM of $K^+, Fe^[3+}, Mg^{2+}, \; or \; Na^+$. slightly increased the activity. The enzyme preparation was heavily affected by most of inhibitors tested such as 1 mM of EIITA, NaCN and pentachlorophenol, and completely inactivated by p-CMB and TCA of 1 mM, or 10 mM.

• Parasites, Hosts and Diseases
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• v.36 no.2
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• pp.133-142
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• 1998

A 40 kDa cysteine protease was purified from the crude extract of adult worms of GMnnophalloines seoi by two consecutive steps: Sephacryl S-200 HR and DEAE- Sephacel chromatography. Enzyme activities were completely inhibited by cysteine protease inhibitors, L-lorans-epoxysuccinylleucylamido (4-guanidino) butane (E-64) and iodoacetic acid, strongly suggesting that the purified enzyme belongs to the cysteine family of proteases. The enzyme was maximally acive at pH 4.5 in 0.1 M of buffer, and its activity was greatly potentiated in the presence of 5 mM dithiothreitol. The protease degraded macromolecules with differential capabilities : it degraded extracellular matrix proteins, such as collagen and fibronectin, with a stronger activity against collagen than fibronectin . However, the enzyme digested hemoglobin and human immunoglobulins only slightly. leaving them nearly intact after an overnight reaction. Our results suggest that the cysteine protease of G. seoi adults is potentially significant in the nutrient uptake from the host intestine.

• Applied Biological Chemistry
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• v.26 no.1
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• pp.41-46
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• 1983

The characteristics of crude polyphenol oxidase extracted from mushroom[Tricholoma matsutake(S. Ito et Imai) Sing.] were investigated. The enzyme showed highest affinity to pyrogaroll among trihydroxyphenols. Except for o-diphenols the enzyme was inactive in di-and monophenols. The optimum pH was about 4 and the optimum temperature ranged from 45 to $55^{\circ}C$. The enzyme activity was completely inhibited by $70^{\circ}C$ heat treatment for 2 min. $Cu^{++}$, $Fe^{++}$ and $Mg^{++}$ activated the enzyme at low concentration($10^{-1}mM$), but inhibited at high concentration (1mM). The most potent inhibitors were Na-diethyldithiocarbamate, L-ascorbic acid, L-cysteine and NaCl. The Km value with pyrogaroll was 0.88mM.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1705-1713
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• 2012

A gene encoding ${\beta}$-glucosidase was cloned from Weissella cibaria 37, an isolate from human feces. Sequence analysis showed that the gene could encode a protein of 415 amino acids in length, and the translated amino acid sequence showed homology (34-31%) with glycosyl hydrolase family 1 ${\beta}$-glucosidases. The gene was overexpressed in E. coli BL21(DE3) using pET26b(+) and a 50 kDa protein was overproduced, which matched well with the calculated size of the enzyme, 49,950.87 Da. Recombinant ${\beta}$-glucosidase was purified by using a his-tag affinity column. The purified ${\beta}$-glucosidase had an optimum pH and a temperature of 5.5 and $45^{\circ}C$, respectively. Among the metal ions (5mM concentration), $Ca^{2+}$ slightly increased the activity (108.2%) whereas $Cu^{2+}$ (46.1%) and $Zn^{2+}$ (56.7%) reduced the activity. Among the enzyme inhibitors (1 mM concentration), SDS was the strongest inhibitor (16.9%), followed by pepstatin A (45.2%). The $K_m$ and $V_{max}$ values of purified enzyme were 4.04 mM and 0.92 ${\mu}mol/min$, respectively, when assayed using pNPG (p-nitrophenyl-${\beta}$-D-glucopyranoside) as the substrate. The enzyme liberated reducing sugars from carboxymethyl cellulose (CMC).

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1388-1394
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• 2012

A xylanase-producing thermophilic strain, Geobacillus sp. TC-W7, was isolated from a hot spring in Yongtai (Fuzhou, China). Subsequently, the xylanase gene that encoded 407 amino acids was cloned and expressed. The recombinant xylanase was purified by GST affinity chromatography and exhibited maximum activity at $75^{\circ}C$ and a pH of 8.2. The enzyme was active up to $95^{\circ}C$ and showed activity over a wide pH range of 5.2 to 10.2. Additionally, the recombinant xylanase showed high thermostability and pH stability. More than 85% of the enzyme's activity was retained after incubation at $70^{\circ}C$ for 90 min at a pH of 8.2. The activity of the recombinant xylanase was enhanced by treatment with 10 mM enzyme inhibitors (DDT, Tween-20, 2-Me, or TritonX-100) and was inhibited by EDTA or PMSF. Its functionality was stable in the presence of $Li^+$, $Na^+$, and $K^+$, but inhibited by $Hg^{2+}$, $Ni^{2+}$, $Co^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $Pb^{2+}$, $Fe^{3+}$, and $Al^{3+}$. The functionality of the crude xylanase had similar properties to the recombinant xylanase except for when it was treated with $Al^{2+}$ or $Fe^{2+}$. The enzyme might be a promising candidate for various industrial applications such as the biofuel, food, and paper and pulp industries.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.448-453
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• 2000

During the screening of inhibitors of caspase-3 induction in U937 human monocytic leukemia cells from natural sources, Petasites japonicum, which showed a high level of inhibition was selected. The inhibiting compound was purified from the methanol extract by Sephadex LH-20 column chromatography and HPLC. The inhibitor was identified as [3-(3,4-dihydroxyphenyl)-2-oxopropyl]ester, petasiphenol, by spectroscopic methods of UV, EIMS, $^1H-NMR$, $^{13}C-NMR$ and HMBC. It showed a caspase-3 inducing inhibitory activity at $8\;{\mu}g/ml$ of $IC_{50}$ value with DNA fragmentation inhibition in U937 human leukemia cells. It also showed a free radical scavenging ability of 1,1-diphenyl-2-picrylhydrazyl.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.84-90
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• 1994

Kinetic parameters of various substrates and inhibitors were measured to elucidate the binding requirements of the active site of intracellular adenosine deaminase (ADA) in Aspergillus oryzae. 3'-Deoxyadenosine was the best substrate according to the value of relative kcat/$K_m$. Purine riboside was found to be the strongest inhibitor with the $K_i$ value of $3.7{\times}10^{-5}$M. Adenine acted neither as a substrate nor as an inhibitor, suggesting the presence of ribose at N-9 of adenosine was crucial to binding. ADA also catalyzed the dechlorination of 6-chloropurine riboside, generating inosine and chloride ions. Substrate specificity of 6-chloropurine riboside was 0.86% of adenosine. Purine riboside, a competitive inhibitor of ADA, inhibit the dechlorination with similar $K_i$ value, suggesting that the same binding site was involved in deamination and dechlorination. Among the sulfhydryl group reagents, mercurials, pchloromercuribenzoate (PCMB), mersalyl acid and $HgCl_2$ inactivated the enzyme. Mersalyl acid-inactivated ADA was reactivated by thiol reagents, but PCMB-inactivated enzyme was not. When ADA was treated with the mercurial reagents, the inhibition constants and inhibition patterns were determined. Each inhibition was competitive with substrate. The $K_i$ values of these mercurial reagents were lower in 10 mM phosphate buffer than in 100 mM phosphate buffer, showing phosphate dependency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.321-329
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• 1993

The present study was conducted to elucidate the body modulating function of fermented seafood products. Angiotensin converting enzyme (ACE) acts in blood pressure regulation, converting angiotensin I to the potent vasoconstrictor angiotensin II and inactivating the vasodilator bradykinin to raise blood pressure. Salted and fermented anchovy which is one of the traditional fermented seafood in Korea was tested for inhibitory activity against ACE. ACE inhibitory activity of salted anchovy during the period of fermentation was increased with the elapse of fermentation days until fermentation of 60 days, but thereafter decreased inversely. When the fermented product was extracted with $50\%$ ethanol, the ACE inhibitory activity was the highest. And the ACE inhibitory activity was proportion to the content of $50\%$ ethanol soluble peptide-nitrogen of the fermented product. From the profiles of gel permeation chromatography on a Bio-Gel P-2 of $50\%$ ethanol soluble fraction obtained from salted and fermented anchovy fermented for 60 days at an ambient temperature, the higher activity fractions were C'($IC_{50}=97{\mu}g\;protein/ml$) and D'($IC_{50}=65{\mu}g\;protein/ml$). Amino acid analysis showed that the large quantify of threonine, glutamic acid, lysine for C' and serine, proline for D', respectively.

• Natural Product Sciences
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• v.14 no.2
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• pp.143-146
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• 2008

Protein tyrosine phosphatase 1B (PTP1B) is emerging as a potential therapeutic target for the treatment of type-2 diabetes and obesity. To search for new types of PTP1B inhibitors, we have undertaken in vitro enzyme assay for some anthraquinones and stilbenes isolated from plants. Of the anthraquinones tested, physcion (1), 1-O-methylemodin (2), and emodin (3) showed high activities, with $IC_{50}$ values of 7.6, 7.0, and $3.8{\mu}g/mL$, respectively, while the anthraquinone glycosides, physcion-8-O-${\beta}$-D-glucopyranoside (4) and emodin-8- O-${\beta}$-D-glucopyranoside (5), were less active than their aglycones. All the stilbenens (6 - 15) slightly inhibited PTP1B activity at high concentration of $30{\mu}g/mL$. Our findings suggest that the hypoglycemic effect of anthraquinones may be associated with their PTP1B inhibitory activity.