• 제목/요약/키워드: Disordered structure

검색결과 113건 처리시간 0.032초

Intrinsically disordered fold of a PIAS1-binding domain of CP2b

  • Jo, Ku-Sung;Jo, Hae-Ri;Kim, Chul Geun;Kim, Chan-Gil;Won, Hyung-Sik
    • 한국자기공명학회논문지
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    • 제18권1호
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    • pp.30-35
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    • 2014
  • The transcription factor CP2 regulates various biological systems at diverse tissues and cells. However, none of the four CP2 isoforms has been solved in structure yet. In particular, two different regions of the CP2b isoform have been characterized to interact with the PIAS1 in nucleus to regulate the ${\alpha}$-globin gene expression. Among them, in this study, the region encompassing residues 251-309 of CP2b was prepared as a recombinant protein and its solution structure was characterized by NMR spectroscopy. The results indicated that the CP2b(251-309) fold belongs to typical IDRs (intrinsically disordered regions), likely to facilitate promiscuous interactions with various target proteins. Unfortunately, however, its interaction with the N-terminal domain of PIAS1 (residues 1-70), which has been identified as one of the CP2b-binding sites, was not observed in the NMR-based titration experiments. Therefore, it could be postulated that the 251-309 region of CP2b would not contact with the PIAS1(1-70), but alternatively interact with another CP2b-binding region that encompasses residues 400-651 of PIAS1.

컴퓨터 분석에 의한 Myosin Head의 SH가 Actin-Myosin Cross-Bridges에 따른 구조변화 연구 (The Structure Change Study on the Actin-Myosin Cross-Bridges in SH of Myosin Head by The Computer Data)

  • 김덕술;옥수열;박근호
    • 한국응용과학기술학회지
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    • 제22권1호
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    • pp.84-90
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    • 2005
  • IASL(iodo acetamide) and MSL(maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. Equatorial refiection(10,11) change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of 143${\AA}$ and 72${\AA}$ could offer information of the mass projection of population of myosin heads along the :filament axis. The slope of intensity profile of the mass projection of 143${\AA}$ and reflection of IASL is appeared and that of MSL is appeared sharply. The decrease of 215${\AA}$ reflection intensity is appeared the periodical characteristic of 143${\AA}$ reflection by spin label. The raise of MSL actin reflection at 51${\AA}$ and 59${\AA}$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we could conclude that LASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.

Myosin Head의 Spin Label이 온도 영향에 따른 구조 변화 연구 (Study of Structure Change by Temperature Effect in Spin Label of Myosin Head)

  • 김덕술;박근호
    • 한국응용과학기술학회지
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    • 제20권3호
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    • pp.268-273
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    • 2003
  • IASL(iodo acetamide spin label) and MSL(maleimide spin label) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. The muscle was isometrically tetanized with three trains of 3ms pulses every 50ms between $5^{\circ}C$ with $25^{\circ}C$. Equatorial reflection change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of $143{\AA}$ and $72{\AA}$ could offer information of the mass projection of population of myosin head along the filament axis. The slope of intensity profile of the mass projection of $143{\AA}$ and reflection of IASL is appeared and that of MSL is appeared sharply. The decrease of $215{\AA}$ reflection intensity the periodical character of $143{\AA}$ reflection by spin label. The raise of MSL actin reflection at $51{\AA}$ and $59{\AA}$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we can conclude that IASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.

비순서화된 스트림 처리를 위한 슬라이딩 윈도우 기법 (Processing Sliding Windows over Disordered Streams)

  • 김현규;김철기;김명호
    • 한국정보과학회논문지:데이타베이스
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    • 제33권6호
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    • pp.590-599
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    • 2006
  • 비순서화된 스트림은 슬라이딩 윈도우의 생성에 있어서 두 가지 문제점을 야기한다. 첫째는 스트림을 효율적으로 정렬하는 문제이며, 둘째는 정렬된 스트림으로부터 윈도우를 언제 생성할지 결정하는 문제이다. 본 논문에서는 이러한 문제를 해결하기 위한 윈도우 오퍼레이터의 구조와 방법에 대해 제안한다. 먼저 입력 튜플을 효율적으로 정렬하고 저장하기 위해 인덱스를 이용한 오퍼레이터의 구조를 소개한다. 그리고 윈도우의 생성 시점을 결정하기 위한 평균-기반 추정 방식을 제안한다. 제안하는 기법에서는 추정에 필요한 매개변수를 질외문에서 정의할 수 있으며, 이를 통해 사용자가 어플리케이션의 요구사항에 따라 정확성이나 응답 시간과 같은 질의 결과의 특성을 조절할 수 있도록 지원한다. 본 논문의 실험 결과는 제안한 평균-기반 방식이 기존의 연구에서 이용한 방식보다 적응성과 안정성이 우수하다는 것을 보인다.

A Combined Rietveld Refinement on the Crystal Structure of a Magnetoelectric Aurivillius Phase $Bi_5Ti_3FeO_{15}$ Using Neutron and X-ray Powder Diffractions

  • Ko, Tae-Gyung;Jun, Chang-Ho;Lee, Jeong-Soo
    • The Korean Journal of Ceramics
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    • 제5권4호
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    • pp.341-347
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    • 1999
  • An ambiguity on the correct room temperature structure of $Bi_5Ti_3FeO_{15}$ was resolved using a combined Rietveld refinement of neutron and X-ray diffraction. The structure of this compound has been reported to have a space group of F2mm (adopting 2-fold rotation symmetry along the c-axis) or A21am. However, our diffraction, study reveals that some reflections would violate F-centering and confirm that the belong to $A2_1$am. Out refinement with the space group of $A2_1$am converged at $R_p=6.85%, R_wp=9.23%$ and $\chi^2$=1.66 for an isotropic temperature model with 85 variables. The lattice constants are a=5.4677(1) $\AA$, b=5.4396(1) $\AA$, and c=41.2475(8)$\AA$. In structure, Ti/Fe atoms at the oxygen octahedral sites of the perovskite unit are completely disordered, resulting in that these atoms are transparent in neutron diffraction. The octahedra of the perovskite unit are relatively displaced along the a-axis against the Bi atoms, which contribute as a major component to the spontaneous polarization of $Bi_5Ti_3FeO_{15}$.

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Loose and Dense Aggregate Particle Packing Models in Cement and Concrete

  • Kim, Jong-Cheol;Lim, Chang-Sung;Auh, Keun-Ho
    • The Korean Journal of Ceramics
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    • 제6권1호
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    • pp.1-5
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    • 2000
  • Particle packing properties are important to develop high technology products in the field of cement and concrete. Two types of particle packing models for aggregates with sand and cement were introduced: the loose and the dense aggregate packing. Aggregate packing models with randomly generated sand and cement particles in the interstices of aggregates fit the Furnas model very well. Different aggregate models show different packing properties with the experimental results. Main reason for the difference with the experimental results is due to sand rearrangement in the loose aggregate packing model and to aggregate relaxation in the dense aggregate packing model. In the experimental situation, aggregates seem to be more disordered and have a relaxed packing structure in the dense packing, and sands seem to have a more rearranged packing structure in the loose packing model.

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고분해능 투과전자현미경 연구에 의한 ${\gamma}$-Al2O3의 상 전산모사 (Compouter Image Simulation of ${\gamma}$-Al2O3 in High-Resolution Transimission Electron Microscopy)

  • 이정용
    • 한국세라믹학회지
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    • 제26권2호
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    • pp.276-288
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    • 1989
  • Interpretation of high-resolution transmission electron microscopy images of defects and complex structures such as found in ceramics generally requires matching of the images with compound image simulations for reliable interpretation. A transmission electron microscopy study of the aluminum oxide was carried out at high-resolution, so that the crystal structure of the aluminum oxide could be modelled on an atomic level. In conjunction with computer simulation comparisons, the images reveal directly the atomic structure of the oxide. Results show that comparison between experimental high-resolution electron microscopy images and simulated images leads to a one to one correspondence of the image to the atomic model of the aluminum oxide. The aluminum atoms are disordered in the octahedral sites and the tetrahedral sites in the spinel aluminum oxide.

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Ultrahigh Vacuum Study for the Model Systems of Ziegler-Natta Catalyst

  • 이창섭
    • Bulletin of the Korean Chemical Society
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    • 제16권7호
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    • pp.661-666
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    • 1995
  • The surface structure of the adsorption site for the identification of active sites involved in the Ziegler-Natta catalyst was studied by surface science techniques. As an example of a real catalyst, TiCl3 single crystals were prepared in a gradient furnace designed for this study and characterized by Auger Electron Spectroscopy (AES) and Low Energy Electron Diffraction (LEED) under ultrahigh vacuum condition. The chlorine covered Ti (0001) surface was employed as a model catalyst for the study of Ziegler-Natta catalyst. The diffuse LEED (DLEED) technique for the surface structural determination was applied to this disordered chlorine adsorbed on Ti (0001) surface. The diffuse scattering intensities were measured by a TV-computer method using a low light level video camera. From an analysis of two catalyst systems, the informations for the surface structure of the model catalyst surfaces were derived.

Synthesis and Analysis of Ge2Sb2Te5 Nanowire Phase Change Memory Devices

  • 이준영;김정현;전덕진;한재현;여종석
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.222.2-222.2
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    • 2015
  • A $Ge_2Sb_2Te_5$ nanowire (GST NW) phase change memory device is investigated with Joule heating electrodes. GST is the most promising phase change materials, thus has been studied for decades but atomic structure transition in the phase-change area of single crystalline phase-change material has not been clearly investigated. We fabricated a phase change memory (PCM) device consisting of GST NWs connected with WN electrodes. The GST NW has switching performance with the reset/set resistance ratio above $10^3$. We directly observed the changes in atomic structure between the ordered hexagonal close packed (HCP) structure and disordered amorphous phase of a reset-stop GST NW with cross-sectional STEM analysis. Amorphous areas are detected at the center of NW and side areas adjacent to heating electrodes. Direct imaging of phase change area verified the atomic structure transition from the migration and disordering of Ge and Sb atoms. Even with the repeated phase transitions, periodic arrangement of Te atoms is not significantly changed, thus acting as a template for recrystallization. This result provides a novel understanding on the phase-change mechanism in single crystalline phase-change materials.

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결정구조에 의한 $Ba(Mg_{1/3}Nb_{2/3})O_3$ - $La(Mg_{2/3}Nb_{1/3})O_3$고용체의 마이크로파 유전 특성 (Microwave Dielectric Characteristics of $Ba(Mg_{1/3}Nb_{2/3})O_3$ - $La(Mg_{2/3}Nb_{1/3})O_3$ Solid Solutions with Crystal Structure)

  • 백종후;임은경;이미재;최병현;남산
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.738-743
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    • 2004
  • The microwave dielectric properties and their related structural characteristics in solid solutions of (1-x) $Ba(Mg_{1/3}Nb_{2/3})O_3$ -x $La(Mg_{2/3}Nb_{1/3})O_3$ (BLMN) have been investigated by measuring the dielectric constant${\varepsilon}r)$, Q value and temperature coefficient of resonant frequency$({\tau}f)$ and by observing the crystal structure using high resolution transmission electron microscopy (HRTEM). Microwave dielectric properties showed characteristic features for specific composition. Dielectric constant$({\varepsilon}r)$ showed maximum value at the composition which corresponds to the phase boundary between 1:2 ordered and 1:1 ordered structure. The increase in ${\varepsilon}_r$ may be caused by the rattling of ions by incorporating smaller ions and the disordered structure. The variation of temperature coefficient of resonant frequency${{\tau}_f)$ was investigated in terms of oxygen octahedra tilting.

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