• Title/Summary/Keyword: 단일가닥

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Real-time Fluorescence Assay of DNA Polymerase Using a Graphene Oxide Platform (산화 그래핀 플랫폼을 이용한 DNA 중합효소의 실시간 형광에세이)

  • Gang, Jongback
    • Microbiology and Biotechnology Letters
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    • v.41 no.4
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    • pp.456-461
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    • 2013
  • Using the different adsorption properties of ssDNA and dsDNA to GO, this study used a real time and efficient fluorescence assay to detect the enzymatic activity of the Klenow fragment with the adsorbed DNA to GO. Results showed that adsorption of fluorescein-tagged ssDNA to GO resulted in fluorescence quenching and DNA was released from GO by adding complementary DNA. In addition, fluorescence restoration was increased through a polymerization reaction by the Klenow fragment in the presence of a fluorescein-attached template, GO, and primer. Gel electrophoresis was conducted to confirm the hybridization and DNA polymerization reactions on GO.

Identification of Meiotic Recombination Intermediates in Saccharomyces cerevisiae (효모 감수분열과정에서의 유전자 재조합 기전 특이적 DNA 중간체의 구조 변화)

  • Sung, Young Jin;Yoon, Sang Wook;Kim, Keun Pil
    • Korean Journal of Microbiology
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    • v.49 no.1
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    • pp.1-7
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    • 2013
  • During meiosis, genetic recombinants are formed by homologous recombination accompanying with the programmed double-strand breaks (DSBs) and strand exchanges between homologous chromosomes. The mechanism is generated by recombination intermediates such as single-end invasions (SEIs) and double-Holliday junctions (dHJs), and followed by crossover (CO) or non-crossover (NCO) products. Our study was focused on the analysis of meiotic recombination intermediates (DSBs, SEIs, and dHJs) and final recombination products (CO and NCO). We identified these meiotic recombination intermediates using DNA physical analysis under HIS4LEU2 "hot spot" system in budding yeast, Saccharomyces cerevisiae. For DNA physical analysis, when the hot spot locus is recognized by restriction enzyme from synchronous meiotic cells, the fragmented DNA that are forming recombination intermediates can be detected and quantified through Southern hybridization analysis. Our study suggests that this system can analyze the structural change of recombination intermediates during DSB-SEI transition, double-Holiday junctions and crossover/non-crossover products in meiosis.

Anterior Cruciate Ligament Reconstruction with a Four-Strand Single Semitendinosus Tendon Autograft (반건양건 단일 4가닥을 이용한 전방십자인대 재건술)

  • Kyung, Hee-Soo;Kim, Tae-Gong;Oh, Chang-Wug;Yoon, Sang-Hyup
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.2
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    • pp.138-142
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    • 2009
  • Purpose: The purpose of this study was to evaluate the result of anterior cruciate ligament (ACL) reconstruction using a fourstrand single semitendinous tendon to decrease the donor site morbidity due to harvest both semitendinosus and gracilis tendon. Materials and Methods: Thirty seven consecutive patients who had underwent ACL reconstruction using four-strand single semitendinosus tendon were evaluated. Mean age was 28.6 years old. Male was 34, female 3 patients. Time from injury to surgery was 5.4 months. Combined injuries were 10 meniscus injuries, 3 medial collateral ligament injuries and 1 osteochondral injury. Mean follow-up period was 16 months(12~18 months). Clinical evaluation was done using range of motion, Lachman test, pivot-shift test, Lysholm score & KT-2000 arthrometer. Results: All patients showed the normal range of motion of mean 150..at follow-up. Lachman test and pivot-shift test was negative in 35 cases. Lysholm score was improve from 84 to 92. Two cases had residual laxity due to poor compliance. Mean anterior translation compared to contralateral side by KT-2000 arthrometer improved from 6.7 mm preoperatively to 2.1 mm at follow-up. Conclusion: Reconstruction of the anterior cruciate ligament with use of a four-strand single semitendinosus tendon autograft showed good clinical results.

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Kinetic Measurement of the Step Size of DNA Unwinding by Bacteriophage T7 DNA Helicase gp4 (T7 박테리오파지 gp4 DNA helicase에 의한 DNA unwinding에서 step size의 반응속도론적 측정)

  • Kim, Dong-Eun
    • Journal of Life Science
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    • v.14 no.1
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    • pp.131-140
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    • 2004
  • T7 bacteriophage gp4 is the replicative DNA helicase that unwinds double-stranded DNA by utilizing dTTP hydrolysis energy. The quaternary structure of the active form of T7 helicase is a hexameric ring with a central channel. Single-stranded DNA passes through the central channel of the hexameric ring as the helicase translocates $5'\rightarrow3'$ along the single-stranded DNA. The DNA unwinding was measured by rapid kinetic methods and showed a lag before the single-stranded DNA started to accumulate exponentially. This behavior was analyzed by a kinetic stepping model for the unwinding process. The observed lag phase increased as predicted by the model with increasing double-stranded DNA length. Trap DNA added in the reaction had no effect on the amplitudes of double-stranded DNA unwound, indicating that the $\tau7$ helicase is a highly processive helicase. Global fitting of the kinetic data to the stepping model provided a kinetic step size of 10-11 bp/step with a rate of $3.7 s^{-1}$ per step. Both the mechanism of DNA unwinding and dTTP hydrolysis and the coupling between the two are unaffected by temperature from $4∼37^{\circ}C$. Thus, the kinetic stepping for dsDNA unwinding is an inherent property of tile replicative DNA helicase.

Analysis of Higher Order Structure of 5S rRNA from Pseudomonas alcaligenes by using Pb(Ⅱ) Ion (Pb(Ⅱ) 이온을 이용한 Pseudomonas alcaligenes 5S rRNA의 고차원 구조 분석)

  • Kim, Sangbumn;Lee, Younghoon;Park, Inwon
    • Journal of the Korean Chemical Society
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    • v.39 no.6
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    • pp.453-458
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    • 1995
  • We have applied Pb2+ to the structural analysis of 5S rRNA from Pseudomonas alcaligenes. The mode of Pb2+-induced clevage on 5S rRNA has shown several specific features which may be utilized for the examination of tertiary structure of 5S rRNA: Pb2+ does not attack the stable helical stems; single stranded regions or bulges are attacked in variable susceptibilities depending on the positions of the sequences or the bases on the molecule; unstable helical region d is not attacked at all; only 3' sided strand of unstable helical stem C is weakly attacked, leaving 5' sided strand unattacked. Based on the Pb2+ cleavage properties and the structural analysis of Xanthomonas celebensis 5S rRNA, we have proposed a working hypothesis for the tertiary interactions in 5S rRNA.

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원형 브레이드 강화 일가소성 복합재료의 역학적 특성 연구(II)

  • 이덕래;김학용;최종주;서민강
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.299-302
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    • 1998
  • Textile composite란 직물, 편성물, 브레이드, 3축포 등의 텍스타일 제품을 강화재로 사용한 섬유강화 복합재료의 충칭으로서 텍스타일이 지닌 뛰어난 기능을 matrix에 부가함으로서 단일재료로서는 얻지 못하는 뛰어난 공업재료를 만들 수 있다. 브레이드는 3가닥 이상의 실이 서로 교착하여 2축포를 형성하며, 조성과정에서 중앙사를 삽입하면 3축포가 된다. (중략)

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A Study of Error Detection and Repair on DNA Duplicate Structure (DNA 이중나선구조에서의 오류 검출 및 복구방법연구)

  • Kim, Soke-Hwan;Hur, Chang-Wu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.327-330
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    • 2011
  • 살아있는 생명체는 세포로 구성되며 성장 분열을 통해 스스로 복제할 수 있는 능력을 지녔다. DNA 상의 변이, 즉 돌연변이는 자손의 생존과 번식에 불리하게 작용할 수 있고 이점을 줄 수 있는 양면성을 지녔다. 본 연구에서는 DNA 이중나선은 복제 주형으로 사용되기 위해서는 먼저 이중나선이 열리고 단일 가닥으로 분리되어야 한다. 이중 나선구조결합에서의 결합의 오류부분의 위치를 찾아내고 복구하는 방법을 제시한다.

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