• 제목/요약/키워드: K_{cat}/K_m$

검색결과 394건 처리시간 0.029초

한국 토종 단모종 고양이에서 Mycoplasma Haemofelis 감염 증례 (A Case of Mycoplasma haemofelis Infection in a Korean Domestic Shorthair Cat)

  • 김미령;이승진;이근우
    • 한국임상수의학회지
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    • 제31권1호
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    • pp.57-60
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    • 2014
  • 6개월령의 한국토종단모고양이가 발열, 빈호흡, 식욕부진, 체중감소로 내원하였다. 고양이는 10일 전 Fellocel$^{(R)}$ 백신을 접종받은 이후 증상을 보였다. 신체검사 결과 공막의 황달과 호흡곤란을 호소했다. 혈액혈구검사와 혈액화학검사에서 빈혈, 혈소판감소증, 백혈구증가증, 고빌리루빈혈증이 관찰되었다. 혈액도말 검사와 기타 검사를 통해 심한 용혈을 확인할 수 있었고 고양이 용혈성 빈혈을 감별진단 하기위해 Erhlichia, Hemobartonella, FeLV, FIV, Anaplasma PCR 검사를 의뢰하였다. PCR 검사 결과 Mycoplasma haemofelis 특이 208 bp의 양성밴드가 확인되었고, 다른 질병은 음성으로 진단되었다. 고양이는 4주 동안 Doxycycline을 사용하였고 급성기 1주 동안에는 prednisolone을 같이 사용하였다. 임상증상은 약물투여 4일째부터 호전되기 시작하였고 이후 PCR 재검을 통해 완치를 확인하였다. 이것은 M. haemofelis 감염 고양이의 진단을 확인하고 완치한 국내 첫 증례이다.

Effect of Ionic Liquid on the Kinetics of Peroxidase Catalysis

  • Lee, Yoon-Mi;Kwon, O-Yul;Yoo, Ik-Keun;Ryu, Keun-Garp
    • Journal of Microbiology and Biotechnology
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    • 제17권4호
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    • pp.600-603
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    • 2007
  • The effect of a water-miscible ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate $([BMIM][BF_4])$, on the horseradish peroxidase (HRP)-catalyzed oxidation of 2-methoxyphenol (guaiacol) with hydrogen peroxide $(H_2O_2)$ was investigated. HRP maintains its high activity in the aqueous mixtures containing various concentrations of the ionic liquid and even in 90% (v/v) ionic liquid. In order to minimize the effect of solution viscosity on the kinetic constants of HRP catalysis, the enzymatic reactions in the subsequent kinetic study were performed in water-ionic liquid mixtures containing 25% (v/v) ionic liquid at maximum. As the concentration of $[BMIM][BF_4]$ increased for the oxidation of guaiacol by HRP, the $K_m$ value increased with a slight decrease in the $K_{cat}$ value: The $K_m$ value increased from 2.8 mM in 100% (v/v) water to 22.5mM in 25% (v/v) ionic liquid, indicating that ionic liquid significantly weakens the binding affinity of guaiacol to HRP.

Cloning and Expression of Thermostable $\beta$-Glycosidase Gene from Thermus filiformis Wai33 A1 in Escherichia coli and Enzyme Characterization

  • Kang, Sang-Kee;Cho, Kwang-Keun;Ahn, Jong-Kun;Kang, Seung-Ha;Han, Kyung-Ho;Lee, Hong-Gu;Choi, Yun-Jaie
    • Journal of Microbiology and Biotechnology
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    • 제14권3호
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    • pp.584-592
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    • 2004
  • A thermostable $\beta$-glycosidase gene, tfi $\beta$-gly, was cloned from the genomic library of Thermus filiformis Wai33 A1. ifi $\beta$-gly consists of 1,296 bp nucleotide sequence and encodes a polypeptide of 431 amino acids. It shares a strong amino acid sequence similarity with the $\beta$-glycosidases from other Thermus spp. belonging to the glycosyl hydrolase family 1. In the present study, the enzyme was overexpressed in Escherichia coli BL21 (DE3) using the pET21b(+) vector system. The recombinant enzyme was purified to homogeneity by heat treatment and a $Ni^{2+}$-affinity chromatography. Polyacrylamide gel electrophoresis (PAGE) showed that the recombinant Tfi $\beta$-glycosidase was a monomeric form with molecular mass of 49 kDa. The temperature and pH range for optimal activity of the purified enzyme were 80- $90^{\circ}C$ and 5.0-6.0, respectively. Ninety-three percent of the enzyme activity was remained at $70^{\circ}C$ after 12 h, and its half-life at $80^{\circ}C$ was 6 h, indicating that Tfi $\beta$-glycosidase is highly thermostable. Based on its K_m$, or $K_{cat}K_m$, ratio, Tfi $\beta$-glycosidase appeared to have higher affinity for $\beta$-D-glucoside than for $\beta$-D-galactoside, however, $K_{cat} for \beta$-D-galactoside was much higher than that for $\beta$-D-glucoside. The activity for lactose hydrolysis was proportionally increased at $70^{\circ}C$ and pH 7.0 without substrate inhibition until reaching 250 mM lactose concentration. The specific activity of Tfi TEX>$\beta$-glycosidase on 138 mM lactose at $70{^\circ}C$ and pH 7.0 was 134.9 U/mg. Consequently, this newly cloned enzyme appears to have a valuable advantage of conducting biotechnological processes at elevated temperature during milk pasteurization in the production of low-lactose milk.

수종강심약물(數種强心藥物)과 부자(附子)"부타놀" 분획(分劃)이 심장근(心臟筋)의 기계적(機械的) 성질(性質)에 미치는 영향(影響) (Effects of Aconiti tuber butanol fraction and several cardiotonics on the mechanical properties of cat papillary muscle preparation)

  • 윤충
    • 대한약리학회지
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    • 제12권1호
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    • pp.45-55
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    • 1976
  • The effect of positive inotropic agents on the contractile properties of myocardial muscle were studied in the cat papillary muscle preparation. For the purpose, the effects of ouabain $(1{\times}10^{-6}g/ml)$, norepinephrine (0.05r/m1) and Aconiti tuber butanol fraction (AF(5), $1{\times}10^{-4}$, $5{\times}10^{-4}$, $1{\times}10^{-3}$, $2{\times}10^{-3}g/ml$) on the contractile dynamics of the papillary muscle preparation isolated from right ventricle of cat were observed in terms of the characteristics of isometric twitch and the lengh-tension relation, the force-velocity relation and the load-extension relation of the series elastic component of contractile model of A.V. Hill. All the studied inotropic drugs similary increased the rate and the intensity of the developed isometric tension, while shortened the time from onset of contraction to peak tension and the total duration of contraction. In the afterloaded simultaneous isotonic and isometric contraction, they also similary increased the maximal velocity of shortening accompanied with the increasing the maximum developed force. In the load-extension relation all the drugs, however, had no appreciable influence on the properties of the series elastic component. Increasing the concentration, Aconiti tuber butanol fraction produced more pronounced effect on all the studied parameters of isometric and isotonic contraction of cat papillary muscle preparation. From the aspect of contractile dynamics, it seemed that the positive inotropic effect of ouabain, norepinephrine and Aconiti tuber butanol fraction are similary achieved through an influence on the behavior of the contractile component only.

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한방호흡재활치료를 시행한 만성폐쇄성폐질환 환자 2례 (Chronic Obstructive Pulmonary Disease Patients Treated with Korean Medicine Pulmonary Rehabilitation: Two case reports)

  • 김태현;이수원;유이란;이은정;정인철;박양춘
    • 대한한의학회지
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    • 제41권3호
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    • pp.162-172
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    • 2020
  • Objectives: The purpose of study was to report the clinical improvement of Chronic Obstructive Pulmonary Disease (COPD) patients treated with Korean medicine pulmonary rehabilitation. Methods: The patients were treated with Lung-conduction exercise, Chuna manual therapy, Exercise therapy. To assess the treatment outcomes, we used the pulmonary function test (PFT), modified medical research council scale (mMRC), 6-minute walk distance (6MWD), peak expiratory flow rate (PEFR), COPD assessment test (CAT), St. George respiratory questionnaire (SGRQ). Results: After treatments, the patient's clinical symptoms were improved with CAT, SGRQ's significant decrease and PFT, mMRC, 6MWD and PEFR were maintained or improved slightly. Conclusions: The Korean medicine pulmonary rehabilitation was effective in the treatment of COPD patients. This study suggested the possibility of Korean Medicine pulmonary rehabilitation program in the clinic.

Gene Transcription in the Leaves of Rice Undergoing Salt-induced Morphological Changes (Oryza sativa L.)

  • Kim, Dea-Wook;Shibato, Junko;Agrawal, Ganesh Kumar;Fujihara, Shinsuke;Iwahashi, Hitoshi;Kim, Du Hyun;Shim, Ie-Sung;Rakwal, Randeep
    • Molecules and Cells
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    • 제24권1호
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    • pp.45-59
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    • 2007
  • We describe the gene expression profile of third leaves of rice (cv. Nipponbare) seedlings subjected to salt stress (130 mM NaCl). Transcripts of Mn-SOD, Cu/Zn-SOD, cytosolic and stromal APX, GR and CatB were up-regulated, whereas expression of thylakoid-bound APX and CatA were down-regulated. The levels of the compatible solute proline and of transcripts of its biosynthetic gene, ${\Delta}^1$-pyrroline-5-carboxylate synthetase (P5CS), were strongly increased by salt stress. Interestingly, a potential compatible solute, ${\gamma}$-aminobutyric acid (GABA), was also found to be strongly induced by salt stress along with marked up-regulation of transcripts of GABA-transaminase. A dye-swap rice DNA microarray analysis identified a large number of genes whose expression in third leaves was altered by salt stress. Among 149 genes whose expression was altered at all the times assayed (3, 4 and 6 days) during salt stress, there were 47 annotated novel genes and 76 unknown genes. These results provide new insight into the effect of salt stress on the expression of genes related to antioxidant enzymes, proline and GABA as well as of genes in several functional categories.

쥐 뇌에서 발현되는 S-100 Beta유전자의 Polymorphism에 대한 분자생물학적 증거 (Molecular Evidence for the Presence of Polymorphism in the Gene of S-100 Beta Protein Expressed in Rat Brain)

  • 신송우;권오식;유민
    • 대한의생명과학회지
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    • 제4권2호
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    • pp.137-142
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    • 1998
  • 쥐 뇌에서 발현되는 S-100 beta 유전자의 다형현상을 조사하였다. Polymerase chain reaction을 위한 주형으로는 뇌에서 분리한 mRNA를 직접 역전사한 cDNA, 또는 rat brain cDNA library에서 분리한 phage DNA를 사용하였다. 증폭된 DNA 절편들은 크기가 기존에 보고되었던 것과 일치하였으나 DNA sequencing을 통한 세부적인 분석 결과 coding region 내에 염기변화 (CAT가 CAC로 변함)가 있음이 확인되었다. 그러나 이들은 모두 histidine을 결정하는 유전암호이기에 단백질의 1차구조에는 아무런 영향을 미치지 않는 다형현상으로 결론지어졌다. 본 연구는 S-100 beta 단백질에 그동안 알려지지 않았던 다형현상이 존재함을 시사하는 것으로서 S-100beta 효소 유전자의 전체적인 구조를 이해하기 위한 학문적 자료가 될 것으로 기대된다.

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Infections of Two Isthmiophora Species (Digenea: Echinostomatidae) in Wild Mammals from Republic of Korea with Their Morphological Descriptions

  • Choe, Seongjun;Na, Ki-Jeong;Kim, Youngjun;Jeong, Dong-Hyuk;Yang, Jeong-Jin;Eom, Keeseon S.
    • Parasites, Hosts and Diseases
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    • 제57권6호
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    • pp.647-656
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    • 2019
  • Isthmiophora hortensis (Digenea: Echinostomatidae) is a dominant echinostome in animal reservoir hosts and humans in the Republic of Korea (Korea). We intended to investigate the infection status with this echinostome species in the several species of wild animals and describe the morphological characteristics in the faunistic view point. A total of 175 animal carcasses belonging to 3 families, i.e., Canidae, Felidae and Mustelidae, were collected from the southern regions of Korea from March 2010 to July 2017. Isthmiophora spp. worms were recovered from the small intestines of each animal under a stereomicroscope after washing of intestinal contents. Isthmiophora hortensis was recovered from 4 species of wild carnivores, i.e., Nyctereutes procyonoides (3/107: 2.8%), Mustela sibirica (11/31: 35.5%), Meles lucurus (2/3: 33.3%) and Martes flavigula (1/2: 50%). The other 3 carnivores comprising stray dogs, cat and leopard cat were negative for I. hortensis infection (0/2, 0/10 and 0/12, respectively). Specimens obtained from the Lutra lutra (6/8: 75%) were identified as a distinct species, I. inermis, by morphological comparison. Isthmiophora inermis has thinner body, elongate testes and different anterior limits of vitelline fields. Detailed morphological descriptions and comparisons with the morphological characteristics are provided. Conclusively, it was confirmed for the first time that 3 species of mustelid mammals, i.e., M. sibirica, M. lucurus, and M. flavigula, are to be the new definitive hosts of I. hortensis in Korea. Additionally, I. inermis is to be newly added in the Korean echinostome fauna.

Acute phase protein mRNA expressions and enhancement of antioxidant defense system in Black-meated Silkie Fowls supplemented with clove (Eugenia caryophyllus) extracts under the influence of chronic heat stress

  • Bello, Alhassan Usman;Sulaiman, Jelilat Aderonke;Aliyu, Madagu Samaila
    • Journal of Animal Science and Technology
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    • 제58권11호
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    • pp.39.1-39.12
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    • 2016
  • Background: The current study investigates the anti-stress effects of clove (Eugenia caryophyllus) extracts (0, 200, 400, and 600 mg/kg) on serum antioxidant biomarkers, immune response, immunological organ growth index, and expression levels of acute phase proteins (APPs); ovotransferrin (OVT), ceruloplasmin (CP), ceruloplasmin (AGP), C-reactive protein (CRP), and serum amyloid-A (SAA) mRNA in the immunological organs of 63-d-old male black-meated Silkie fowls subjected to 21 d chronic heat stress at $35{\pm}2^{\circ}C$. Results: The results demonstrated that clove extract supplementation in the diet of Silkie fowls subjected to elevated temperature (ET) improve growth performance, immune responses, and suppressed the activities of glutathion peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and thioredoxin reductase (TXNRD); reduced serum malonaldehyde (MDA) and glutathione (GSH) concentrations when compared with fowls raised under thermoneutral condition (TC). Upon chronic heat stress and supplementation of clove extracts, the Silkie fowls showed a linear increase in GSH-Px, SOD, CAT, and TXNRD activities (P = 0.01) compared with fowls fed diets without clove extract. ET decreased (P < 0.05) the growth index of the liver, spleen, bursa of Fabricius and thymus. However, the growth index of the liver, spleen, bursa of Fabricius and thymus increased significantly (P < 0.05) which corresponded to an increase in clove supplemented levels. The expression of OVT, CP, AGP, CRP, and SAA mRNA in the liver, spleen, bursa of Fabricius and thymus were elevated (P < 0.01) by ET compared with those maintained at TC. Nevertheless, clove mitigates heat stress-induced overexpression of OVT, CP, AGP, CRP and SAA mRNA in the immune organs of fowls fed 400 mg clove/kg compared to other groups. Conclusions: The results showed that clove extracts supplementation decreased oxidative stress in the heat-stressed black-meated fowls by alleviating negative effects of heat stress via improvement in growth performance, antioxidant defense mechanisms, immunity, and regulate the expression of acute phase genes in the liver and immunological organs.

금 나노입자를 회합시킨 수식된 흑연전극으로 NADH의 전기촉매 산화반응 (Electrocatalytic Oxidation of NADH at the Modified Graphite Electrode Incorporating Gold Nano Particles)

  • 차성극;한성엽
    • 전기화학회지
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    • 제10권1호
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    • pp.1-6
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    • 2007
  • 금 나노 입자를 회합시킨 흑연전극 표면에 mercaptopropionic acid(mpa)를 사용하여 자기조립 단층막(self-assembled monolayer: SAMs)을 생성시키고 이어서 도파민(dopa)과의 짝지움 반응을 통하여 Gr(Au)/mpa-dopa형의 수식된 전극을 제작하여 NADH의 전기촉매 산화반응에 적용하였다. 이 수식 전극이 전자전달반응속도와 반응과정에 대하여 연구하였다. 전극 표면에 고정된 도파민이 NADH와 이차반응 속도상수는 회전 전극법으로 0.1 M 인산염 완충용액(pH=7.0)에서 결정하였으며 그 값이 $5.06{\times}10^5M^{-1}s^{-1}$였고, $EC_{cat}$ 및 전자전달이 지배적인 과정이었다. 그러나 반응초기 즉, $10^{-3}s$ 이내에서는 이 전극에서 확산에 영향을 받으며 그 때 확산계수는 $4.64{\times}10^{-4}cm^2s^{-1}$이다.