• 제목/요약/키워드: Complex Enzyme

검색결과 438건 처리시간 0.025초

Cruciferous Vegetables: Dietary Phytochemicals for Cancer Prevention

  • Abdull Razis, Ahmad Faizal;Noor, Noramaliza Mohd
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권3호
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    • pp.1565-1570
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    • 2013
  • Relationships between diet and health have attracted attention for centuries; but links between diet and cancer have been a focus only in recent decades. The consumption of diet-containing carcinogens, including polycyclic aromatic hydrocarbons and heterocyclic amines is most closely correlated with increasing cancer risk. Epidemiological evidence strongly suggests that consumption of dietary phytochemicals found in vegetables and fruit can decrease cancer incidence. Among the various vegetables, broccoli and other cruciferous species appear most closely associated with reduced cancer risk in organs such as the colorectum, lung, prostate and breast. The protecting effects against cancer risk have been attributed, at least partly, due to their comparatively high amounts of glucosinolates, which differentiate them from other vegetables. Glucosinolates, a class of sulphur-containing glycosides, present at substantial amounts in cruciferous vegetables, and their breakdown products such as the isothiocyanates, are believed to be responsible for their health benefits. However, the underlying mechanisms responsible for the chemopreventive effect of these compounds are likely to be manifold, possibly concerning very complex interactions, and thus difficult to fully understand. Therefore, this article provides a brief overview about the mechanism of such compounds involved in modulation of carcinogen metabolising enzyme systems.

Cardioprotective effect of Argyreia speciosa (Burm. f) Boj. extracts against Isoproterenol- induced myocardial infarction in rats

  • Thakker, Shalin;Biradar, S.M.;Habbu, P.V.;Mahadevan, K.M.;Thippeswamy, B.S.;Veerapur, V.P.
    • Advances in Traditional Medicine
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    • 제10권4호
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    • pp.278-287
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    • 2010
  • The present study was undertaken to evaluate the protective effect of ethanol (EtAS), ethyl acetate (EAAS) and aqueous (AQAS) extracts of Argyreia speciosa (AS) roots against Isoproterenol (ISO)-induced myocardial infarction in rats. The animals were exposed to isoproterenol (200 mg/kg. s.c) twice at an interval of 24 hrs. Cardioprotective effect was assessed by observing ECG parameters, serum marker enzymes and histopathology of the heart. Pretreatment of EAAS, and EtAS (200 mg/kg) resulted in a significant (P < 0.001) increase in P wave, QRS complex and R-R interval, whereas heart rate, QT interval and cardiac cycle were maintained near to normal values. EtAS and EAAS showed significant (P < 0.05; P < 0.001) reduction in all the tested diagnostic markers compared to ISO treated group. Histological studies on the structural changes of heart tissue supported the protective activity of AS. The result suggest that treatment of AS prior to ISO has a significant role in protecting the animals from ISO induced myocardial infarction.

Enzymatic N-glycan analysis of 31 kDa molecule in plerocercoid of Spirometra mansoni (sparganum) and its antigenicity after chemical oxidation

  • Chung, Young-Bae;Kong, Yoon;Yang, Hyun-Jong
    • Parasites, Hosts and Diseases
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    • 제42권2호
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    • pp.57-60
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    • 2004
  • A highly specific antigenic protein of 31 kDa from plerocercoid of Spirometra mansoni (sparganum) was obtained by gelatin affinity and Mono Q anion-exchange column chromatography. The purified 31 kDa protein was subjected to N-glycan enzymatic digestion for structural analysis. The relative electrophoretic mobility was analyzed by SDS-PAGE, before and after digestion. On SDS-PAGE after enzymatic digestion, the 31 kDa protein showed a molecular shift of approximately 2 kDa, which indicated the possession of complex N-linked oligosaccharides (N-glycosidase F sensitive) but not of high-mannose oligosaccharides (endo-beta-N-acetylglucosaminidase H, non-sensitive). Chemically periodated 31 kDa protein showed statistically non-significant changes with human sparganosis sera by enzyme linked immunosorbent assay (ELISA). Therefore, the dominant epitopes of the 31 kDa molecule in human sparganosis were found to be mainly polypeptide, while N-glycans of the antigenic molecule in sparganum was minimal in anti-carbohydrate antibody production.

β-Secretase (BACE1) Purification by Refolding Method and Complex with Hispidin

  • Lim, Ji-Hong;Lee, Bo Ram;Park, Hee Won;Hong, Bum Soo;Lim, Beong Ou;Kim, Young Jun
    • 대한화학회지
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    • 제58권6호
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    • pp.553-559
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    • 2014
  • Alzheimer's disease (AD) is a devastating neurodegenerative disease that represents the most common form of dementia among the elderly population. The deposition of aggregated ${\beta}$-amyloid ($A{\beta}$) senile plaques in the human brain is a classic observation in the neuropathology of AD, yet an understanding of the mechanism of their formation remains elusive. $A{\beta}$ is formed through endoproteolysis of the amyloid precursor protein (APP) by ${\beta}$-secretase (BACE1, ${\beta}$-site APP-cleaving enzyme) and ${\gamma}$-secretase. In this study, BACE1 protein was successfully over-expressed, purified, and refolded and utilized in a binding study with hispidin. We developed a simpler refolding method using a urea gradient and size-exclusion gel filtration to purify an active BACE1 protein variant, in larger quantities than that reported previously, and measured the binding affinity of hispidin to the BACE1 protein variant through isothermal titration calorimetry.

Classification, Structure, and Bioactive Functions of Oligosaccharides in Milk

  • Mijan, Mohammad Al;Lee, Yun-Kyung;Kwak, Hae-Soo
    • 한국축산식품학회지
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    • 제31권5호
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    • pp.631-640
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    • 2011
  • Milk oligosaccharides are the complex mixture of six monosaccharides namely, D-glucose, D-galactose, N-acetyl-glucosamine, N-acetyl-galactosamine, L-fucose, and N-acetyl-neuraminic acid. The mixture is categorized as neutral and acidic classes. Previously, 25 oligosaccharides in bovine milk and 115 oligosaccharides in human milk have been characterized. Because human intestine lacks the enzyme to hydrolyze the oligosaccharide structures, these substances can reach the colon without degradation and are known to have many health beneficial functions. It has been shown that this fraction of carbohydrate can increase the bifidobacterial population in the intestine and colon, resulting in a significant reduction of pathogenic bacteria. The role of milk oligosaccharides as a barrier against pathogens binding to the cell surface has recently been demonstrated. Milk oligosaccharides have the potential to produce immuno-modulation effects. It is also well known that oligosaccharides in milk have a significant influence on intestinal mineral absorption and in the formation of the brain and central nervous system. Due to its structural resemblance, bovine milk is considered to be the most potential source of oligosaccharides to produce the same effect of oligosaccharides present in human milk. This review describes the characteristics and potential health benefits of milk oligosaccharides as well as the prospects of oligosaccharides in bovine milk for use in functional foods.

Amplified Fragment Length Polymorphism Fingerprinting as a Tool to Study the Genetic Diversity of Staphylococcus aureus Isolated from Food Sources

  • Kim, Young-Sam;Kim, Jong-Bae
    • 대한의생명과학회지
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    • 제8권1호
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    • pp.39-46
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    • 2002
  • Amplified fragment length polymorphism (AFLP) is a recently developed PCR-based high resolution fingerprinting method that is able to generate complex banding patterns which can be used to delineate intraspecific genetic relationships among bacteria. In this study, we have modified and evaluated a PCR-based technique, amplified fragment length polymorphism (AFLP) analysis, for use in fingerprinting strains of Staphylococcus aureus. Single-enzyme amplified fragment length polymorphism (SE-AFLP) analysis was used to perform strain identification of Staphylococus aureus. By careful selection of AFLP primers, it was possible to obtain reproducible and sensitive identification to strain level. AFLP fingerprinting of 5 reference strains of Staphylococcus aureus and 65 strains of Staphylococcus aureus that were isolated from food sources of different area and diverse genomic types of Staphylococcus aureus were recognized. As a result of this study, we found that the AFLP patterns of Staphylococcus aureus isolated from Seoul, Taejeon and Gwang-Ju indicated the close relation with genetic similarity. The main purpose of this study was to find an alternative and reliable fingerprinting method to study the overall genetic diversity, using Staphylococcus aureus species as an example, and observed if the method can be successfully applied to all staphylococcal species.

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CREB and FoxO1: two transcription factors for the regulation of hepatic gluconeogenesis

  • Oh, Kyoung-Jin;Han, Hye-Sook;Kim, Min-Jung;Koo, Seung-Hoi
    • BMB Reports
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    • 제46권12호
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    • pp.567-574
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    • 2013
  • Liver plays a major role in maintaining glucose homeostasis in mammals. Under fasting conditions, hepatic glucose production is critical as a source of fuel to maintain the basic functions in other tissues, including skeletal muscle, red blood cells, and the brain. Fasting hormones glucagon and cortisol play major roles during the process, in part by activating the transcription of key enzyme genes in the gluconeogenesis such as phosphoenol pyruvate carboxykinase (PEPCK) and glucose 6 phosphatase catalytic subunit (G6Pase). Conversely, gluconeogenic transcription is repressed by pancreatic insulin under feeding conditions, which effectively inhibits transcriptional activator complexes by either promoting post-translational modifications or activating transcriptional inhibitors in the liver, resulting in the reduction of hepatic glucose output. The transcriptional regulatory machineries have been highlighted as targets for type 2 diabetes drugs to control glycemia, so understanding of the complex regulatory mechanisms for transcription circuits for hepatic gluconeogenesis is critical in the potential development of therapeutic tools for the treatment of this disease. In this review, the current understanding regarding the roles of two key transcriptional activators, CREB and FoxO1, in the regulation of hepatic gluconeogenic program is discussed.

이산화탄소의 전기화학적 변환 (Electrochemical Conversion of Carbon Dioxide)

  • 송지은;신운섭
    • 전기화학회지
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    • 제12권2호
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    • pp.131-141
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    • 2009
  • 이산화탄소의 유용한 화합물로의 전환은 온실가스 증가로 인한 기후변화에 따른 환경문제의 해결 뿐 아니라 탄소원의 재활용이란 관점에서 무척 중요하다. 그러나 탄소화합물 중 가장 안정된 이산화탄소를 다른 유용한 화합물로 변환시키기 위해서는 에너지가 투입되어야 하고 효과적인 전환을 위하여 촉매의 개발 및 관련된 반응 조건의 확립이 필요하다. 본 총설에서는 그 동안 전기화학적으로 이산화탄소를 변환시킨 연구 내용들을 전극재료, 무기화합물, 효소를 이산화탄소의 환원 촉매로서 이용한 경우로 나누어 전체적으로 살펴보았다. 선택성이 좋고 효율적이며 안정성을 가진 촉매는 아직 개발되지 않은 상황이므로 앞으로 많은 연구가 진행되어야 할 분야이다.

Erwinia sp.에 의한 Gallic Acid로부터 Pyrogallol의 생산 (Production of Pyrogallol from Gallic Acid by Erwinia sp.)

  • 박병화;황인균;방원기
    • 한국미생물·생명공학회지
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    • 제22권6호
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    • pp.665-671
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    • 1994
  • For the production of pyrogallot from gallic acid, about 100 strains of bacteria capable of assimilating gallic acid as a sole carbon and energy source were isolated from the soil. JH- 004 strain showing the highest activity of gallate decarboxy#lase was selected from them and identi- fied as Erwinia sp. The optimal conditions for the production of pyrogallol from gallic acid were examined. The resting cells of JH-004 cultured in a complex medium containing 0.2%(w/v) gallic acid were prepared after the treatment of the pellet with a freezing and thawing, and used as a enzyme source. The reaction mixtures for the maximal production of pyrogallol were shown to be 6 g/l of resting cells and 15 g/l of gallic acid in 25 mM potassium phosphate buffer. The optimal pH for the reaction was 5.0 and the optimal temperature was 35$\circ$C . Additionally, Triton X-100(0.01%, w/v) was found to be most effective for the production of pyrogallol. Under the above conditions, 10.27 g/l of pyrogallol was produced from 15 g/l of gallic acid after incubation of 35 hrs. This amount of pyrogallol corresponds to a 92.37% yields, based on gallic acid.

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Bergenin 및 Acetylbergenin의 Galactosamine 유발 간독성에 대한 치료효과 (Therapeutic Effects of Bergenin and Acetylbergenin on Galactosamine-induced Hepatotoxicity in Rats)

  • 임화경;최종원;김학성
    • 생약학회지
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    • 제31권3호
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    • pp.351-356
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    • 2000
  • The hepatoprotective effects of bergenin and its derivative, acetylbergenin, were evaluated against D-galactosamine-induced liver damage in rats. Bergenin is a C-glucoside of 4-O-methyl gallic acid that has been isolated from the cortex of Mallotus japonicus (Euphorbiaceae). Acetylbergenin was synthesized from acetylation of bergenin to increase lipophilic and physiological activities. Bergenin (50, 100 and 200 mg/kg) and acetylbergenin (25, 50 and 100 mg/kg) were administered orally once daily for successive 5 days after the injection of galactosamine (400 mg/kg, i.p.), respectively. The substantially elevated serum enzyme activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and ${\gamma}-glutamyltransferase$ due to galactosamine treatment were dose-dependently restored towards normalization by post-treatment with bergenin and acetylbergenin. Bergenin and acetylbergenin also significantly prevented the elevation of hepatic malondialdehyde formation and depletion of reduced glutathione content induced by galactosamine in a dose-dependent manner. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored towards normalization. These results suggest that effects of bergenin and acetylbergenin may be related to complex mechanisms that involve prevention of lipid peroxidation and preservation of hepatic glutathione. The results of this study clearly indicate that bergenin and acetylbergenin have potent hepatotherapeutic action against galactosamine-induced hepatotoxicity in rats, and lipophilic acetylbergenin is more active in the antihepatotoxic effects against galactosamine than much less lipophilic bergenin.

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