• Title/Summary/Keyword: reaction center

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Clearance of False-positive Antigen-Antibody Reactions of a Diagnostic Antigen Production in Escherichia coli with Human Sera

  • Noh, Kap-Soo;Kim, Jong-Wan;Ha, Suk-Hoon;Yoo, Wang-Don;Jeon, Weong-Joong;Kim, Hyun-Su
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제4권1호
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    • pp.63-65
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    • 1999
  • Although many pharmaceutically useful proteins are produced in E. coli expression system, it is very are rare for the system to be used in the production of diagnostic antigen due to a major problem, i.e., false-positive reaction of e. coli host-derived proteins contaminating purified diagnostic antigen with human sera. The N (nucleocapsid) protein of Seoul virus causing haemorrhagic fever with renal syndrome (HFRS) was produced in E. coli BL21 (DE3), and used for the detection of N protein-specific antibodies in human sera. Using the N protein as a diagnostic antigen of HFRS, the false-positive reaction was cleared by merely mixing the test sera with the extract of E. coli host strain not harboring expression plasmid.

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A Facile Synthesis of SAPO-34 Molecular Sieves with Microwave Irradiation in Wide Reaction Conditions

  • Jun, Jong-Won;Lee, Ji-Sun;Seok, Hwi-Young;Chang, Jong-San;Hwang, Jin-Soo;Jhung, Sung-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제32권6호
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    • pp.1957-1964
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    • 2011
  • Various reaction conditions uding temperature, time and type and concentration of templates have been changed in order to facilely synthesize, especially with microwave (MW) heating, SAPO-34 molecular sieves. SAPO-34 molecular sieve can be synthesized rapidly with microwave irradiation from a gel containing tetraethylammonium hydroxide (TEAOH) as a template. However, other several templating molecules lead to SAPO-5 molecular sieve under microwave irradiation even though SAPO-34 is obtained by conventional electric synthesis from the same reactant gels. Moreover, SAPO-34 can be obtained more easily by increasing the TEAOH or silica concentration or by increasing the reaction temperature. SAPO-34 can be obtained within 5 min in a selected condition (high temperature of 210 $^{\circ}C$) with microwave heating, which may lead to a continuous production of the important material. SAPO-34 synthesized by microwave irradiation is homogeneous and small in size and shows acidity and a stable performance in the dehydration of methanol and 2-butanol to olefins, suggesting potential applications in acid catalysis.

Molecular Modeling and Site Directed Mutagenesis of the O-Methyltransferase, SOMT-9 Reveal Amino Acids Important for Its Reaction and Regioselectivity

  • Park, So-Hyun;Kim, Bong-Gyu;Lee, Sun-Hee;Lim, Yoong-Ho;Cheong, You-Hoon;Ahn, Joong-Hoon
    • Bulletin of the Korean Chemical Society
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    • 제28권12호
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    • pp.2248-2252
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    • 2007
  • SOMT-9 is an O-methyltransferase that utilizes quercetin to produce 3'-methoxy quercetin. In order to determine which amino acids of SOMT-9 are important for this reaction and its regioselectivity, molecular docking experiments followed by site directed mutagenesis were performed. Molecular modeling and molecular docking experiments identified several amino acid residues involved in metal binding, AdoMet binding, and substrate binding. Site-directed mutagenesis showed that Asp188 is critical for metal binding and that Lys165 assists other metal binding residues in maintaining quercetin in the proper position during the reaction. In addition, Tyr207 was shown to play an important role in the determination of the regioselectivity and Met60 was shown to be involved in formation of the hydrophobic pocket necessary for substrate binding. The molecular modeling and docking experiments discussed in this study could be applicable to future research including prediction of substrate binding and regioselectivity of an enzyme.

연속 반응시간 과제를 이용한 내재적 운동학습의 특성 연구 (The Study of Implicit Motor Learning Using a Serial Reaction Time Task)

  • 박지원;홍철표;김종만;하현근;김연희
    • 한국전문물리치료학회지
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    • 제11권2호
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    • pp.1-8
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    • 2004
  • Motor skill learning can be acquired implicitly without consciousness of what is being learned. The purpose of this study was to examine the characteristics of implicit motor learning in young and elderly people using a perceptual-motor task. Forty normal young and elderly subjects participated. A modified version of the Serial Reaction Time Task (SRTT) using six blocks of twelve perceptual motor sequences was administered. The paradigm consisted of the first random sequence block followed by the four patterned blocks and another random block. In each block, the go signal consisted of an asterisk displayed in the one of the four parallel arrayed boxes in the middle of the screen. Subjects were instructed to push the corresponding response buttons as quickly as possible. Young subjects demonstrated shorter reaction times during the consecutive patterned blocks reflecting appropriate learning accomplished. Elderly subjects were able to learn a perceptual-motor task with implicit knowledge, but the performance was lower than that of the young persons. These results indicated that implicit sequence learning is still preserved in elderly adults, but the rate of learning is slower.

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수영 출발동작의 지면반력 차이 비교 II (A Comparison of Ground Reaction Force of High School Swimmers in Accordance with Starting Motions)

  • 김규완
    • 한국운동역학회지
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    • 제17권3호
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    • pp.69-80
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    • 2007
  • The purpose of this study was to investigate the difference of ground reaction forces of swimming athletes during their starting motion and to find out the most effective starting motions which were used in swimming athletes. The subjects were 9 male and 8 female high school swimming athletes who were athletic career over 7 years and used three starting motions in competition. The ground reaction forces were measured from each athletes performing three starting motion each of the open grap starting motion, closed grap starting motion and track starting motion. For the measurement, the force platform of AMTI company was utilized, and the analysis on measured ground reaction forces were used of Biosoft(Ver. 1.0). The items measured were stance time, Fz max deceleration force and Fz max deceleration force time, Fz mid stance force and Fz mid stance force time, Fz max acceleration force and Fz max acceleration force time, Torque maximum and Torque maximum time, Torque average, Excursion along Y axis of center of pressure of foot, Excursion along X axis of center of pressure of foot, Length of center of pressure of foot, Average velocity of center of pressure of foot. The data measured by the closed grap starting motion, open grap starting motion and track starting motion were analyzed by one-way repeated ANOVA. The results were as follows ; 1. The Fz max deceleration force time, Fz mid stance force, Fz max acceleration force, Torque maximum and Torque maximum time, Excursion along Y axis of center of pressure of foot, Average velocity of center of pressure of foot were significantly fast and large in the closed grap starting motion then open grap starting motion and track starting motion. 2. The Excursion along Y axis of center of pressure of foot was significantly long in the closed grap starting motion then open grap starting motion and track starting motion.

병열 1차 반응속도식을 이용한 유기성 슬러지 수열탄화 반응온도별 메탄생산퍼텐셜 평가 (Assessment of Methane Potential in Hydro-thermal Carbonization reaction of Organic Sludge Using Parallel First Order Kinetics)

  • 오승용;윤영만
    • 한국환경농학회지
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    • 제35권2호
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    • pp.128-136
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    • 2016
  • BACKGROUND: Hydrothermal carbonization reaction is the thermo-chemical energy conversion technology for producing the solid fuel of high carbon density from organic wastes. The hydrothermal carbonization reaction is accompanied by the thermal hydrolysis reaction which converse particulate organic matters to soluble forms (hydro-thermal hydrolysate). Recently, hydrothermal carbonization is adopted as a pre-treatment technology to improve anaerobic digestion efficiency. This research was carried out to assess the effects of hydro-thermal reaction temperature on the methane potential and anaerobic biodegradability in the thermal hydrolysate of organic sludge generating from the wastewater treatment plant of poultry slaughterhouse .METHODS AND RESULTS: Wastewater treatment sludge cake of poultry slaughterhouse was treated in the different hydro-thermal reaction temperature of 170, 180, 190, 200, and 220℃. Theoretical and experimental methane potential for each hydro-thermal hydrolysate were measured. Then, the organic substance fractions of hydro-thermal hydrolysate were characterized by the optimization of the parallel first order kinetics model. The increase of hydro-thermal reaction temperature from 170℃ to 220℃ caused the enhancement of hydrolysis efficiency. And the methane potential showed the maximum value of 0.381 Nm3 kg-1-VSadded in the hydro-thermal reaction temperature of 190℃. Biodegradable volatile solid(VSB) content have accounted for 66.41% in 170℃, 72.70% in 180℃, 79.78% in 190℃, 67.05% in 200℃, and 70.31% in 220℃, respectively. The persistent VS content increased with hydro-thermal reaction temperature, which occupied 0.18% for 170℃, 2.96% for 180℃, 6.32% for 190℃, 17.52% for 200℃, and 20.55% for 220℃.CONCLUSION: Biodegradable volatile solid showed the highest amount in the hydro-thermal reaction temperature of 190℃, and then, the optimum hydro-thermal reaction temperature for organic sludge was assessed as 190℃ in the aspect of the methane production. The rise of hydro-thermal reaction temperature caused increase of persistent organic matter content.

Acarbose Effect for Dexran Synthesis, Acceptor and Disproportionation Reactions of Leuconostoc mesenteroides B-512FMCM Dextransucrase

  • Kim, Do-Man;Park, Kwan-Hwa;Robyt, John F.
    • Journal of Microbiology and Biotechnology
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    • 제8권3호
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    • pp.287-290
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    • 1998
  • Acarbose effectively inhibited the synthesis of dextran, and the inhibition pattern was a noncompetitive type with a $K_i$ value of 1.35 mM. It also inhibited the disproportionation reaction of dextransucrase with isomaltotriose and decreased the efficiency of the maltose acceptor reaction. Increased concentration of dextransucrase or maltose in reaction digests, however, decreased the degree of inhibition by acarbose.

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Ex vivo High-resolution Optical Coherence Tomography (OCT) Imaging of Pleural Reaction after Pleurodesis Using Talc

  • Ahn, Yeh-Chan;Oak, Chulho;Park, Jung-Eun;Jung, Min-Jung;Kim, Jae-Hun;Lee, Hae-Young;Kim, Sung Won;Park, Eun-Kee;Jung, Maan Hong
    • Journal of the Optical Society of Korea
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    • 제20권5호
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    • pp.607-613
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    • 2016
  • The pleura is known as an end target organ of exposure to toxic environmental materials such as fine particulate matter and asbestos. Moreover, long-term exposure to hazardous materials can eventually lead to fatal lung disease such as diffuse pleural fibrosis or mesothelioma. Chest computed tomography (CT) and ultrasound are gold standard imaging modalities for detection of advanced pleural disease. However, a diagnostic tool for early detection of pleural reaction has not been developed yet due to difficulties in imaging ultra-fine structure of the pleura. Optical coherence tomography (OCT), which provides cross-sectional images of micro tissue structures at a resolution of 2-10 μm, can image the mesothelium with a thickness of ~100 μm and therefore enables investigation of the early pleural reaction. In this study, we induced the early pleural reaction according to a time sequence after pleurodesis using talc, which has been widely used in the clinical field. The pleural reaction in talc grouped according to the time sequence (1st, 2nd, 4th weeks) showed a significant thickening (average thickness: 45 ± 7.5 μm, 80 ± 10.7 μm, 90 ± 12.5 μm), while the pleural reaction in sham and normal groups showed pleural change from normal to minimal thickening (average thickness: 16 ± 5.5 μm, 17 ± 4.5 μm, 15 ± 6.5 μm, and 12 ± 7.5 μm, 13 ± 2.5 μm, 12 ± 3.5 μm). The measurement of pleural reaction by pathologic examinations was well-matched with the measurement by OCT images. This is the first study for measuring the thickness of pleural reactions using a biophotonic modality such as OCT. Our results showed that OCT can be useful for evaluating the early pleural reaction.

Direct Triazine Herbicide Detection Using a Self-Assembled Photosynthetic Reaction Center from Purple Bacterium

  • Nakamura, Chikashi;Hasegawa, Miki;Shimada, Kazumi;Shirai, Makoto;Miyake, Jun
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제5권6호
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    • pp.413-417
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    • 2000
  • In this study, a direct detection system for triazine derivative herbicides was developed using the photosynthetic reaction center (RC) from the purple bacterium, Rhodobacter sphaeroides, and surface plasmon resonance (SPR) apparatus. The histidine-tagged RCs were immobilized on an SPR gold chip using nickel-nitrilotriacetic acid groups as a binder for one of the triazine herbicide, atrazine. The SPR responses were proportional to the sample concentrations of atrazine in the range 0.1-1 $\mu\textrm{g}$/mL. The sensitivity of the direct detection of atrazine using the RC-assembled sensor chip was higher than that using the antibody-immobilized chip. The other types of herbicides, DCMU or MCPP, were not detected with such high sensitivity. The results indicated the high binding selectivity of the RC complex.

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Antibacterial Activity of Lysozyme-Galactomannan Conjugate against Escherichia coli

  • Hwang, Jae-Kwan;Kim, Hyun-Jin;Park, Moon-Jung;Shin, Hae-Hun;Pyun, Yu-Ryang
    • Preventive Nutrition and Food Science
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    • 제3권4호
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    • pp.320-323
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    • 1998
  • Lysozyme was covalentyl conjugated with galactomannan through a amino-carbonyl reaction between the lysine $\varepsilon$-amino groups of lysozyme and the reducing ends of galactomannan at a relative humidity of 79% and 6$0^{\circ}C$. The resulting lysozyme-galactomannan conjugate (LGC) was investigated for its antibacterial activity against Escherichia coli. Lysozyme alone did not exhibit antibacterial activity against E. coli. in contrast , significant bactericidal effect was observed for LGC, depending on the reaction temperature. The degree of conjugation between lysozyme and galactomannan was dependent on the incubation time, which affected the antibacterial efficiency against E. coli. This study demonstrated that the amino-carbonyl reaction between lysozyme and galactomannan could be a potential tool to modify lysozyme toward broadening its antibacterial spectrum to Gram-negative bacteria.

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