• Title, Summary, Keyword: 효소활성도

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Characterization of the enzymatic property of thermostable carboxypeptidase Taq by addition of metal ions and replacement of active center metal (금속이온 첨가와 활성중심 금속의 치환에 따른 내열성 카르복시펩 티다제 Taq의 효소적 특성 변화에 관한 연구)

  • Lee, Sang-Hyeon;Ha, Jong-Myung;Ha, Bae-Jin
    • Journal of Life Science
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    • v.12 no.6
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    • pp.682-687
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    • 2002
  • We analyzed improvement on the enzyme activity of CPase Taq by addition of various metal ions. The enzyme activity was increased more then four times by 1 mM cobalt ion and almost three times by 1 mM calcium ion. However, the active center metal zinc ion did not affect the enzyme activity. In order to investigate whether the active center metal affects the enzyme activity, zinc ion which is occupied the active center of the enzyme was replaced by cobalt ion which activates the enzyme activity very effectively. Since the cobalt ion in the active center of the cobalt-substituted CPase Taq did not affect the enzyme activity, it could act as the natal metal ion in the active center of the enzyme.

뇌조직으로부터 정제한 Glutamate decarboxylase의 활성부위 구조 연구

  • 최수영;이수진;장상호;이길수;위세찬
    • Proceedings of the Korean Society of Applied Pharmacology
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    • pp.270-270
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    • 1994
  • 돼지 뇌조직으로부터 순수 분리 정제된 Glutamate decarboxylase (GAD)는 효소 dimer당 0.8mole 보조 인자인 pyridoxal-5-phosphate(PLP)가 강하게 binding되어 있었다. 이러한 부분적으로 resolved된 효소에 외부로부터 PLP를 넣어주면 효소의 활성도는 최대값으로 증가하였다. 정제된 GAD는 sulfydryl시약에 의한 화학변형에 의하여 효소의 활성도를 상실하였으며 환원제인 dithiothreitol이나 2-mercaptoethanol의 첨가에 의하여 효소의 활성도가 복구되는 것으로 보아 효소의 활성부위의 활성에 직접 관여하는 중요한 cysteinyl잔기가 존재하고 있는 것을 알 수 있다.

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Characteristics of Extracellular $\beta$-Glucosidase in Tricholoma matsutake (송이의 세포외 분비 $\beta$-Glucosidase 효소의 특성)

  • 민응기;한영환
    • KSBB Journal
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    • v.15 no.1
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    • pp.9-13
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    • 2000
  • In order to determine the characteristics of $\beta$-glucosidase associated with cellulose degradation, the enzyme produced extracellularly by the mycelia of Tricholoma matsutake DGUM 26001 in culture broth was partially purified. The enzyme activity was maintained in the range of temperatures trom 55 to $70^{\circ}C$ and its optimum temperature was $65^{\circ}C$. The $\beta$-glucosidase enzyme showed relatively high activity in the range of pH 3.0-5.0 and its optimum pH was 4.0. Under the optimal conditions, the specific activity of $\beta$-glucosidase for salicin as a substrate was 18.7 unit/mg protein. After thermal treatment of the enzyme at $55^{\circ}C$ for 60 min, more than 90% of the enzyme activity was still sustained. Iron($Fe^{++}$) stimulated enzyme activity, whereas mercury($Hg^{++}$) and copper($Cu^{++}$) inhibited. Compared to salicin as a substrate, the relative activity for cellobiose was observed to be 48.6%. The apparent $K_m$ and $V_{max}$ of the enzyme with cellobiose were 0.12 mM and 0.02 umol/min, respectively.

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Detection of Zymogenic ChsC Activity in Vegetative Hyphae of Aspergillus nidulans. (Aspergillus nidulans 영양균사에서 효소전구체형 ChsC 활성의 검출)

  • 박범찬;박윤희;박희문
    • Korean Journal of Microbiology
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    • v.40 no.2
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    • pp.178-182
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    • 2004
  • In the vegetative hyphae of Aspergillus nidulans, a zymogenic form of the class I chitin synthase activity was successfully measured by the assay condition for Saccharomyces cerevisiae class I chitin synthase, Chsl. The class I chitin synthase activity of the A. nidulans chsC wild type strain was increased about six-fold by trypsin-pretreatment, but that of the chsC disruption strain revealed no increase. Interestingly enough, level of the class I chitin synthase activity of the chsC disruption strain was almost the same as that of the chsC wild type without trypsin-pretreatment. These results indicated that the A. nidulans ChsC activity could be measured by account-ing the class I chitin synthase activity without the trypsin-pretreatment as an internal control. Consistence to the expression pattern of the chsC revealed by northern blot analysis, the activity of ChsC was increased upon reaching the culture time for acquiring developmental competence. Our results shown here also supported the previous report suggesting the possible involvement of ChsC in vegetative hyphal growth of A. nidulans.

Change of Antioxidant Enzymes Activities in Leaves of Soybean(Glycine max) during Water Stresses and Following Recovery (대두에서 수분장해 및 회복시 엽중 항산화효소의 활성 변화)

  • Kang, Sang-Jae;Kim, Tae-Sung;Park, Woo-Churl
    • Korean Journal of Soil Science and Fertilizer
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    • v.32 no.2
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    • pp.164-170
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    • 1999
  • This experiment was carried out to elucidate change of antioxidant enzymes activities subjected to water stresses in soybean plant. In this study, we measured the activities of ascorbate peroxidase(APDX), monodehydroascorbate reductase(MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase(GR) subjected to drought or flooding stresses for 4days and following recovery for 3days. Leaves of two soybean lines subjected to drought or flooding showed premature senescence as evidenced by the decrease in water content and total soluble protein content but those of soybean leaves was increased when stresses were recovered for 3days. The activities of APDX and GR subjected to drought or flooding were the decrease but those of enzymes were recovered when water stress was recovered. The activities of MDHAR with drought or flooding were on the decrease, whereas those of DHAR were increased, respectively. Antioxidant contents decreased continually subjected to drought or flooding but it recovered after 3 days subjected to water stresses.

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Lipoxygenase Activity of Milled Fractions from Brown Rice (현미 도정획분의 Lipoxygenase 활성)

  • Kim, Ki-Joong;Rhee, Chong-Ouk
    • Korean Journal of Food Science and Technology
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    • v.29 no.1
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    • pp.145-149
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    • 1997
  • Lipoxygenase activity from brown rice varieties (Tongjinbyeo, Kumohbyeo and Kanchukbyeo) was investigated using spectrophotometric method. In all three varieties, there was an increase in the enzyme activity with the reaction time. Enzyme activity was tested at different concentration of the substrate. The $V_{max}\;and\;K_m$ values of Tongjin, Kumoh and Kanchukbyeo were 57.89, 19.85 and 31.38 units/mg protein and 0.054, 0.045 and 0.035 mM. The study of lipoxygenase activity at different pH levels showed that all the varieties had maximal activities around $pH\;7.0{\sim}7.6$. The enzyme activity and specific activity on milled fractions of different brown rice varieties, fraction II was superior to the other fractions and fraction IV was inferior to the other fractions. As the result of microwave heating for 0, 30, 60 and 90 sec, the enzyme activity and specific activity of all the varieties were decreased by the elapse of heating time.

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Changes in the Activities of Nitrate Reductase and Amylase in Response to the Seasons and Cutting in Zoysia Japonica Steud (한국산 잔디에 있어서 계절과 예취에 따른 질산환원효소와 전분분해효소의 활성도 변화)

  • 장남기;김용진
    • Asian Journal of Turfgrass Science
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    • v.3 no.2
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    • pp.95-111
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    • 1989
  • 야외 조건에서 생장한 한국산 들잔디(Zoysia japonica Steud)의 잎, 줄기, 뿌리, 지하경의 관부와 절간에 있어서 질산환원효소 활성도(NRA)와 전분분해효소의 활성도(AA)를 측정하였다. 각 기관에서의 효소 활성도는 4월 중순부터 증가하여 6월의 개화기때 최대값에 도달하였다. 그후 효소 활성도는 급격히 감소하여 겨울철에는 최소에 이르렀다. 이 결과는 잔디의 각 기관에서 NR과 Amylase는 계절적 활성변이를 가진다는 것을 제안한다. NR과 Amylase가 낮은 활성도를 가지는 1986년 7월 31일에 6cm의 높이에서 잔디의 지상부를 예초(cuting)한 결과, 모든 기관에서의 AA와 잎, 줄기에서의 NRA는 2일간의 지연기 후에 급격히 증가하여 7일째에 최대에 이르렀다. 이 값은 대조구의 효소 활성도 보다 약 3배 높았고, 계절적 변이에서의 최대 활성도의 약 90%에 도달하였다. 예초된 잎에서의 조단백질(CP)의 함량은 예초후 7일째 까지 증가하였으나, 건물생산량(DM)과 총가용성 탄수화물(TSC) 함량은 예초후 4,5일 동안 감소하다가 다시 증가하여 7일째에 예초전의 수준에 도달한 후 일정한 값을 유지하였다. 또한 각 기관에서의 NRA와 AA는 예초후 8일째에 정상 수준으로 급감하였다. 이 결과는 완전히 자란 잔디 자체는 NR과 Amylase의 활성에 대한 억제제로서 작용하며, cutting과 같은 외부 성처요인이 개체 수준에서 적용되었을때 손상된 물질을 회복하기 위하여 분자 수준에서 수준에서 효소가 활성화 된다는 것을 제안한다.

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Increased Alcohol Decomposition Efficacy of Hoveina dulcis Extract by Carbohydrate-Hydrolyzing Enzymes (당 분해 효소를 이용한 헛개나무 열매 추출물이 알코올 분해에 미치는 영향)

  • Lee, Kyung-Seok;Kim, Ae-Jung;Lee, Ki-Young
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.4
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    • pp.473-479
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    • 2012
  • In this study, increased alcohol decomposition efficacy (ADH) of Hoveina dulcis extract by Carbohydrate-Hydrolyzing Enzymes was investigated. Carbohydrate decomposition enzymes such as Maxinvert (Invertase), Optidex L-400 (Glucoamylase) and Rohament CL (Cellulase & Pectinase) were added to Hoveina dulcis extract at different concentrations (0.01, 0.05, 0.1, 0.5 and 1%) for 48 hrs, after which samples were taken every 6 hrs for determination of ADH activity. As the enzyme concentration became higher, ADH activity also increased. Especially, the addition of 1% Rohament CL increased enzyme activity to 76% at 30 hrs incubation, after which the increase in activity stopped. In the rat and human body experiment, enzymatic decomposition of Hovenia dulcis extract by addition of 1% Rohament CL was also effective in decreasing serum alcohol concentration and respiration. Especially, in the early stage after alcohol consumption, the efficacy of enzyme treatment of Hovenia dulcis extract was more effective. These results show that if the glycoside forms of active compounds such as flavonols in Hovenia dulcis extract are converted into aglycone forms, alcohol decomposition capability can be enhanced.

Effects of Albizziae Cortex Pharmacopuncture Extracts on the Collagenase Activity and Procollagen Synthesis in HS68 Human Fibroblasts and Tyrosinase Activity (합환피(合歡皮) 약침액(藥鍼液)의 사람 피부아세포의 콜라게나제 활성 및 프로콜라겐 합성과 티로시나제 활성에 미치는 영향)

  • Leem, Kang-Hyun
    • Journal of Acupuncture Research
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    • v.28 no.2
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    • pp.125-131
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    • 2011
  • 목적 : 본 연구는 합환피약침액(合歡皮藥鍼液)이 사람 피부 섬유아세포의 콜라게나제 활성 및 프로콜라겐 합성에 미치는 영항과 티로시나제 활성에 미치는 효과를 측정하고자 실시하였다. 방법 : HS68 사람 정상 섬유아세포에 UVB 조사 후 합환피(合歡皮) 약침액(藥鍼液)가 type I procollagen 생성과 콜라게나제 효소활성에 미치는 효능과 티로시나제 효소활성에 미치는 효능을 평가하였다. 결과 : 합환피약침액(合歡皮藥鍼液)은 UVB 조사된 세포의 콜라게나제 효소활성을 통계적으로 유의하게 억제하였고, 티로시나제 활성을 통계적으로 유의하게 억제하였다. 그러나 티로시나제 억제활성의 정도는 미백효능으로 활용하기에 약간 약한 경향이 있었다. 결론 : 합환피약침액(合歡皮藥鍼液)의 콜라게나제 억제효능은 주름개선 약침치료에 활용이 가능할 것으로 생각된다.

Changes in Esterase Isozyme Activity After Pesticides Treatment in Digestive Juice of Monochamus saltuarius (Gebler) Adult (북방수염하늘소(Monochamus saltuarius) 성충의 살충제 처리에 따른 소화 효소의 활성 변화)

  • Park, Yong-Chul;Cho, Sae-Youll
    • The Korean Journal of Pesticide Science
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    • v.11 no.3
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    • pp.179-185
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    • 2007
  • Esterase isozymes were investigated from digestive juice of M. saltuarius adults after pesticide treatment. Twelve esterase isozymes were separated on 12% native-PAGE gel and stained with three different substrates(${\alpha}$-naphthyl acetate, ${\beta}$-naphthyl acetate, and ${\alpha}$-naphthyl butyrate). Interestingly, the isozyme of Est1(${\alpha}$-naphthyl acetate) was strongly inhibited by the carbofuran and methomyl. The Est1 activity was completely inhibited by the chlorpyrifos and partially inhibited by methidation about 70 %. In addition, eserine suppressed esterase isozyme activities of Est1 about 70% and isozyme activities of Est2, Est3, and Est4 were weakly inhibited. ${\alpha}$-pinene did not suppressed esterase isozyme activities but activities of esterases were very weakly inhibited in camphor and bornyl acetate.