• 제목/요약/키워드: Enzyme inhibition

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Streptomyces 속 균주가 생성하는 Trypsin Inhibitor (제2보) 저해물질의 생물학적 작용상 (Trypsin Inhibitor from Streptomyces sp. (Part 2) Biological Activities or the Inhibitor)

  • Yi, Dong-Heui;Seu, Jung-Hwn
    • 한국미생물·생명공학회지
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    • 제10권4호
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    • pp.283-288
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    • 1982
  • Streptomyces속 균이 생산하는 trypsin inhibitor의 trypsin에 대한 반응성을 조사해 본 결과 본 저해물질은 crystalline trypsin (20.000 unit, hog pancreas)에 대하여 1/8량에서 약 50%의 저해률을 나타내었으며 trypsin에 대한 저해양상은 mixed noncompetitive-competitive inhibition type이었으며 enzyme-inhibitor complex를 빨리 형성하는데 반응액중 isoleucine이 공존하면 활성이 증가되였으며 Ag$_{+}$ Hg$_{++}$등의 금속ion은 강하게 본 저해물질의 작용을 억제하였다. 저해률은 사용한 기질의 종류에 따라 차이가 나서 albumin을 사용하였을 때는 casein이나 hemoglobin을 사용하였을 때보다 저해률이 높았다. 그러고 혈액의 응고에 대해서도 저해작용을 나타내었다.

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큰방가지똥 추출물의 항당뇨 및 항고혈압효과 (Antidiabetes and Angiotensin Converting Enzyme Inhibitory Activity of Sonchus asper (L) Hill Extract)

  • 허명록;왕란;허계방;왕명현
    • 생약학회지
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    • 제42권1호
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    • pp.61-67
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    • 2011
  • In this study, we evaluated the bioactivities of methanol extract and its solvent fractions of Sonchus asper (L.) Hill. The EtOAc fraction of S. asper exhibited more strong antioxidant activity than other extracts as evidenced by the strongest 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity with a $EC_{50}$ value at $33.55\;{\mu}g/mL$ and reducing power, the total polyphenol (180.71 mg GAE/g) and flavonoid contents (145.86 mg QE/g) of S. asper extract were higher than other extracts. The EtOAc fraction of the S. asper also showed 47.38% mushroom tyrosinase inhibition activity, 56.22% ${\alpha}$-glucosidase inhibition and 46.58% ${\alpha}$-amylase inhibition ratio at 1 mg/mL. Both methylene chloride and EtOAc fractions of methanol extract of S. asper effectively reduced of the 86.34% and 62.03% angiotensin I converting enzyme (ACE) activity at 2 mg/mL, respectively. These findings suggest that the EtOAc fraction of the S. asper could be a potential antioxidant in food additive, medicinal, and industry product.

비스테로이드 항염제 (Nonsteroidal Anti-inflammatory Drugs)

  • 이충기
    • Journal of Yeungnam Medical Science
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    • 제17권1호
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    • pp.1-11
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    • 2000
  • Inhibition of cyclooxygenase(COX), and thus prevention of the formation of prostaglandins, provided a unifying explanation of the therapeutic and toxic actions of nonsteroidal anti-inflammatory drugs (NSAIDs). Recently, the discovery of the two isoforms of COX was made by molecular biologists studying neoplastic transformation in chick embryo cells. The constitutive enzyme, COX-1, is obviously responsible for the production of prostaglandins involved in housekeeping functions such as maintenance of integrity of the gastric mucosa, renal blood flow and platelet aggregation. The inducible form of COX (COX-2) is responsible for the formation of prostaglandins that pathologically affects inflammation, pain and fever. Clearly, all the experimental and clinical data support the hypothesis that the beneficial effects of NSAIDs are due to inhibition of the COX-2 enzyme, whereas the gastrotoxicity is due to inhibition of COX-1. The cox-2/COX-1 ratios of the NSAIDs in common use have been measured and compared with epidemiological data on their side effects. There is little evidence to suggest that one NSAID is clearly more effective than another, But substantial individual variability is present with respect to the pharmacology and pharmacokinetics of these drugs: therefore it is essential to adjust the dosage and choose specific drug to the patient's response.

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Correlations in the results of virus neutralization test, hemagglutination inhibition test, and enzyme-linked immunosorbent assay to determine infectious bronchitis virus vaccine potency

  • Park, Mi-Ja;Joh, Seong-Joon;Choi, Kang-Seuk;Kim, Aeran;Seo, Min-Goo;Song, Jae-Young;Yun, Seon-Jong
    • 대한수의학회지
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    • 제56권3호
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    • pp.189-192
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    • 2016
  • The virus neutralization (VN) test was used to determine potency of the infectious bronchitis (IB) vaccine. The results of VN, hemagglutination inhibition (HI), and enzyme-linked immunosorbent assay (ELISA) were compared with those of the IBV M41. The $r^2$ values between VN and HI titers and the ELISA antibody titer were 0.8782 and 0.0336, respectively, indicating a high correlation between VN and HI, but not VN and ELISA. The Cohen's kappa coefficient between the VN titer of 2 $log_{10}$ and HI titer of 5 $log_2$ was 0.909. Our results showed that VN could be replaced with HI for testing the potency of IBV M41.

장내의 탄수화물과 지방 흡수 억제를 통한 체지방 및 비만 개선 효과에 관한 연구 (Beneficial effects of body fat and obesity through the inhibition of the digestion of carbohydrate and lipid in gastrointestinal tract)

  • 정은희;윤승원;이홍석;윤유식;유경미;황인경
    • 한국식품조리과학회지
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    • 제19권1호
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    • pp.107-113
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    • 2003
  • In a previous study, a dietary supplement was developed in our lab using natural herbal extracts against digest enzyme activity in GI tract for weight control. This natural herbal extracts could regulate absorption of glucose and lipid by the inhibition of digest enzyme activity. In this study, we screened the natural herbs that inhibit glucoamylase activity and developed an water extract of cinnamon. The cinnamon extract delayed and decreased the increment of carbohydrate degradation through the inhibition of glucoamylase activity in vitro. Fifty volunteers were subjected to the intake of the herbal extracts by taking twice a day for 60 days. As a result, the treated subjects lost 3 kg of body weight and 3.5 kg of body fat mass after the treatment. Furthermore, the body mass index and waist size were significantly decreased during the experimental period. Above results suggested that the administration of the dietary additives composed of cinnamon and natural herbal extract improves the obesity by the decrement of body weight and body fat mass.

Regulatory Mechanism of L-Alanine Dehydrogenase from Bacillus subtilis

  • 김수자;김유진;서미란;전봉숙
    • Bulletin of the Korean Chemical Society
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    • 제21권12호
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    • pp.1217-1221
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    • 2000
  • L-alanine dehydrogenase from Bacillus subtilis exhibits allosteric kinetic properties in the presence of $ZN^{2+}$. $ZN^{2+}$ induces the binding of substrate (L-alanine) to be cooperative at pH 8.0. The effect of pH variation between pH 7.0 and pH 10.0 on the inhibition by $ZN^{2+}$ correlates with the pH effect on the $K_m$ values for L-alanine within these pH range indicating that $ZN^{2+}$ and substrate compete for the same site. No such cooperativity is induced by $ZN^{2+}$ when the reaction is carried out at pH 10. At this higher pH, $ZN^{2+}$ binds with the enzyme with lower affinity and noncompetitive with respect to L-alanine. Inhibition of L-alanine dehydrogenase by $ZN^{2+}$ depends on the ionic strength. Increase in KCI concentration reduced the inhibition, but allosteric property in $ZN^{2+}$ binding is conserved. A model for the regulatory mechanism of L-alanine dehydrogenase as a noncooperative substrate-cooperative cofactor allosteric enzyme, which is compatible in both concerted and the sequential allosteric mechanism, is proposed.

α-Glucosidase inhibitory caged xanthones from the resin of Garcinia hanburyi

  • Jin, Young Min;Kim, Jeong Yoon;Lee, Soo Min;Tan, Xue Fei;Park, Ki Hun
    • Journal of Applied Biological Chemistry
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    • 제62권1호
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    • pp.81-86
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    • 2019
  • A yellow resin (gamboge) from Garcinia hanburyi has been widely used as folk medicine due to its antibacterial and antitumor activities. We isolated four ${\alpha}$-glucosidase inhibitory compounds from the methanol extract of gamboge. The compounds (1-4) were identified as gambogoic acid (1), moreollic acid (2), gambogic acid (3), and 10-methoxygambogenic acid (4), respectively through spectroscopic data including 2D-NMR and HREIMS. All compounds were examined in the enzyme inhibition assay against ${\alpha}$-glucosidase to identify their inhibitory potencies and kinetic behavior. All compounds (1-4) showed enzyme inhibition against ${\alpha}$-glucosidase, but the activity was significantly affected by the methoxy group on C-10 of ring A and pentenyl pyran moiety of ring D. For example, compound 1 ($IC_{50}=41.4{\mu}M$) bearing pyran ring eight times effective that 4 ($IC_{50}=350.6{\mu}M$) having geranyl group itself. Most active compound was found out to be gambogoic acid (1) which was analyzed most abundant metabolite in gamboge by LC-ESI-MS/MS. In kinetic study, compounds 1 and 2 were proved as noncompetitive inhibitors.

Enzymatic Characteristics of steroid $\Delta^1$-dehydrogenase from Arthrobacter simplex

  • Lee, Mi-Kyung;Bae, Moo
    • Journal of Microbiology and Biotechnology
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    • 제4권2호
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    • pp.119-125
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    • 1994
  • Steroid $\Delta^1$-dehydrogenase purified from hydrocortisone-induced cells of Arthrobacter simplex converted various 3-ketosteroids into their corresponding $\Delta^1$-dehydrogenated products. The transformation efficiencies depend upon the chemical structure of the steroids, especially length of the side chain at 17 position and hydroxyl groups at 11 and 17 positions. The Km values for androstenedione, the most favorable substrate examined, and hydrocortisone were 74 ${\mu}M$ and 294 ${\mu}M$, respectively. The optimum temperature and pH of the enzyme reaction were 35$^{\circ}C$ and pH 9, respectively, and the enzyme was relatively stable at the range from 20 to 35$^{\circ}C$ and from pH 5 to 10 after one hour of incubation. The enzyme activity was markedly inhibited in the presence of $Cu^{2+},\;Fe^{3+},\;Hg^{2+},\;Mo^{6+}$ ions, and somewhat inhibited by $Zn^{2+}$ and $Fe^{2+}$. $\alpha,\alpha'$-Dipyridyl that inhibits 9$\alpha$-hydroxylase and accumulates 1,4-androstadiene-3,17-dione from sterols revealed no inhibitory effect on this enzyme. EGTA showed inhibitory effect. $\beta$-Estradiol competitively inhibited the enzyme activity. Chemical modifications of the enzyme were attempted with several reagents. p-Hydroxymer-curibenzoate showed inhibition of the enzyme activity and protection of the substrate. This suggests that cysteine residue may be involved in the active site of the enzyme.

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Zymomonas mobilis ZM1이 생산하는 균체외 Levansucrase의 정제 및 특성 (Purification and Characterization of an Extracellular Levansucrase from Zymomonas mobilis ZM1(ATCC 10988).)

  • 송기방;서정우;주현규;이상기
    • 한국미생물·생명공학회지
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    • 제26권4호
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    • pp.309-315
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    • 1998
  • An extracellular levansucrase, which catalyzes the formation of levan from sucrose, from the culture broth of Zymomonas mobilis ZM1 was purified by conventional column purification methods. The final purification yield was 18.3 fold of the crude enzyme from Z. mobilis, with 16.5 % of the enzyme recovered in the preparation step. The molecular weight of the enzyme was estimated to be 91,000 by Superose 12 gel filtration, and 45,000 by SDS-PAGE, indicating that levansucrase is a dimer. The optimum pH for the enzyme activity was around pH 4.0 for sucrose hydrolysis, and was around pH 5.0 for levan formation. The enzyme was inhibited by some metal ions, such as Hg$\^$2+/ and Cu2$\^$2+/, and 50% of inhibition was observed with 5mM EDTA. The enzyme activity was enhanced by the presence of detergent Triton X-100, but inhibited by SDS completely The enzyme catalyzes the liberation of reducing sugars, oligosacccharides and the formation of fructose polymer(levan). The enzyme also catalyzes the transfructosylation reaction of fructose moiety from sucrose to various sugar acceptor molecules, including sugar alcohols.

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Comparative Biochemical Properties of Proteinases from the Hepatopancreas of Shrimp. -II. Purification of Trypsin from the Hepatopancreas of Penaeus orientalis-

  • Oh Eun-Sil;Kim Doo-Sang;Jung Kyoo-Jin;Pyeun Jae-Hyeung;Heu Min-Soo;Kim Hyeung-Rak
    • Fisheries and Aquatic Sciences
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    • 제1권2호
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    • pp.209-215
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    • 1998
  • Trypsin-like enzyme was purified from shrimp hepatopancreas through Q-Sepharose ionic exchange, benzamidine Sepharose-6B affinity, and Superdex 75 gel chromatography. Purity of trypsin-like enzyme was increased 69-fold with $44\%$ yield. The enzyme consisted of a single polypeptide chain with a molecular weight (M.W.) of 32 kDa judged by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was completely inactivated by serine enzyme inhibitors such as soybean trypsin inhibitor (SBTI), tosyl-L­lysine chloromethyl ketone (TLCK), and leupeptin. However, the enzyme was not affected by tosyl-L-phenylalanine chloromethyl ketone (TPCK) which is a chymotrypsin specific inhibitor. The enzyme had no activity against benzoyl-tyrosine ethyl ester (BTEE) which is a chymotrypsin specific substrate. The enzyme showed high activity on the carboxyl terminal of Phe, Tyr. Glu, Arg, and Asp. However. no activity was detected against the carboxyl terminal of Pro, Trp, Cys, Gly, Val, and Ala.

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