• 제목/요약/키워드: conformation analysis

검색결과 235건 처리시간 0.047초

기체 분리용 고분자 분리막의 분자동력학 연구 (Molecular Dynamics (MD) Study of Polymeric Membranes for Gas Separation)

  • 박치훈;김득주;남상용
    • 멤브레인
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    • 제24권5호
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    • pp.341-349
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    • 2014
  • 분자 동력학(Molecular dynamics; MD) 전산모사 기술은 대상이 되는 입자(일반적으로, 원자)의 위치와 속도를 계산하여, 원자 및 분자들의 다양한 구조 및 동적 특성을 분석하는 데에 있어서 매우 유용한 기술이다. 기체 분리막 연구에 있어서도 MD는 그동안 free volume 분석, conformation search 등과 같은 고분자 구조 분석 및 permeability, diffusivity와 같은 기체 투과 거동을 연구하는 데 널리 사용되어 왔다. 본 총설에서는 기체 분리막 분야에 MD를 적용하는 일반적인 방법론에 대하여 서술하고, 다양한 관련 연구들을 소개하고자 한다.

인체 tau 유전자의 cDNA 클로닝 및 Escherichia coli에서의 발현 (Cloning and Experssion of a Human tau Gene cDNA in Escherichia coli)

  • 정상호
    • 미생물학회지
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    • 제32권1호
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    • pp.28-33
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    • 1994
  • 정상적인 세포에서 tau 단백질은 신경세포의 축색돌기에 있는 미세소관(microtubule)과 결합하고 있지만, Alzheimer병 세포의 경우 그 단백질은 몇몇 신경세포의 체세포 수지상조직(somatodendrite) 부위에 고착되어서 이중나선 섬유(paired helical filament; PHF)의 주성분을 이루게 된다. 따라서 뇌에PHF가 축적되는 특성 파악과 그들을 야기시키는 요인분석의 일환으로 다량의 순수한 tau 단백질을 확보하기 위하여 본 연구에서는 인체 tau 유전자의 cDNA를 클로닝하고 Escherichia coli에서의 발현을 유도하였다.

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Structural Design and Characterization of a Channel-forming Peptide

  • Krittanai, Chartchai;Panyim, Sakol
    • BMB Reports
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    • 제37권4호
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    • pp.460-465
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    • 2004
  • A 16-residue polypeptide model with the sequence acetyl-YALSLAATLLKEAASL-OH was derived by rational de novo peptide design. The designed sequence consists of amino acid residues with high propensity to adopt an alpha helical conformation, and sequential order was arranged to produce an amphipathic surface. The designed sequence was chemically synthesized using a solid-phase method and the polypeptide was purified by reverse-phase liquid chromatography. Molecular mass analysis by electro-spray ionization mass spectroscopy confirmed the correct designed sequence. Structural characterization by circular dichroism spectroscopy demonstrated that the peptide adopts the expected alpha helical conformation in 50% acetonitrile solution. Liposome binding assay using Small Unilamellar Vesicle (SUV) showed a marked release of entrapped glucose by interaction between the lipid membrane and the tested peptide. The channel-forming activity of the peptide was revealed by a planar lipid bilayer experiment. An analysis of the conducting current at various applied potentials suggested that the peptide forms a cationic ion channel with an intrinsic conductance of 188 pS. These results demonstrate that a simple rational de novo design can be successfully employed to create short peptides with desired structures and functions.

Comparative Molecular Similarity Index Analysis on 2-(indol-5-yl)thiazolederivatives as Xanthine Oxidase(XO)inhibitors

  • Nagarajan, Santhosh Kumar;Madhavan, Thirumurthy
    • 통합자연과학논문집
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    • 제9권3호
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    • pp.190-198
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    • 2016
  • Xanthine Oxidase is an enzyme, which oxidizes hypoxanthine to xanthine, and xanthine to uric acid. It is widely distributed throughout various organsincluding the liver, gut, lung, kidney, heart, brain and plasma. It is involved in gout pathogenesis. In this study, we have performed Comparative Molecular Field Analysis (CoMSIA) on a series of 2-(indol-5-yl) thiazole derivatives as xanthine oxidase (XO) inhibitors to identify the structural variations with their inhibitory activities. Ligand based CoMSIA models were generated based on atom-by-atom matching alignment. In atom-by-atom matching, the bioactive conformation of highly active molecule 11 was generated using systematic search. Compounds were aligned using the bioactive conformation and it is used for model generation. Different CoMSIA models were generated using different alignments and the best model yielded across-validated $q^2$ of 0.698 with five components and non-cross-validated correlation coefficient ($r^2$) of 0.992 with Fisher value as 236.431, and an estimated standard error of 0.068. The predictive ability of the best CoMSIA models was found to be $r{^2}_{pred}$ 0.653. The study revealed the important structural features required for the biological activity of the inhibitors and could provide useful for the designing of novel and potent drugs for the inhibition of Xanthine oxidase.

Structure Identification of 1,2-Disubstituted Chiral Calix[4]arene : X-Ray and NMR Analysis of 25-(3,5-Dinitrobenzoyloxy)-26-methoxy-27,28-dihydroxycalix[4]arene

  • 박영자;신정미;남계춘;김종민;국승근
    • Bulletin of the Korean Chemical Society
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    • 제17권7호
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    • pp.643-647
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    • 1996
  • 1,2-Disubstituted chiral calix[4]arene "25-(3,5-dinitrobenzoyloxy)-26-methoxy-27,28-dihydroxycalix[4]arene" was synthesized by the reaction of 25-(3,5-dinitrobenzoyloxy)-calix[4]arene with methyl iodide in the presence of K2CO3. Methylation was occurred at the 26-position of calix[4]arene. The partial cone conformation and 1,2-substitution were characterized based on the 1H NMR, 13C NMR and X-ray diffraction analysis. The crystal structure has been determined by X-ray diffraction method. The crystals are orthorhombic, Pbca, a=10.652(1), b=17.687(1), c=32.247(3) Å, Z=8, V=6075.4(9) Å3, Dc=1.38gcm-3. The intensity data were collected on an Enraf-Nonius CAD-4 Diffractometer with a graphite monochromated Cu-Kα radiation. The structure was solved by direct method and refined by full-matrix least-squares methods to a final R value of 0.050 for 2368 observed reflections. The molecule is in the partial cone conformation. It has two strong intramolecular hydrogen bonds of O(1D)-H…O(1C)-H…O(1B).

NK-2의 Antagonist인 cyclo-[Gln-Trp-Phe- $\beta$Ala-Leu-Met]의 형태에 관한 연구 (Conformation of cyclo-[Gln-Trp-Phe- $\beta$Ala-Leu-Met], a NK-2 Tachykinin Receptor Antagonist)

  • 하종명
    • 대한화학회지
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    • 제43권5호
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    • pp.540-546
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    • 1999
  • 새로운 NK-2 antagonist이며 고리상 펩티드인 cycIo-($Gln^1-Trp^2-Phe^3-{\beta}Ala^4-Leu^5-Met^6$)의 DMSO 용액 중에서의 형태를 2차원 핵자기공명과 분자동력학적인 계산에 의하여 결정하였다. 조건을 만족시키는 25개의 구조는 모든 아미노산 잔기의 골격원자들 (N,$C^{\alpha}$, C')의 자승 평균 평방근이 $0.02{\AA}$이내로 수렴하였다. 이 고리상 펩티드의 구조는 $Met^6NH$$Ala^4CO$, $Ala^4NH$$Met^6CO$, $Phe^3NH$$Met^6CO$의 사이에 분자내 수소결합이, Gln과 Trp에 type-I ${\beta}$-turn, 그리고 Leu에서 ${\gamma}$-turn을 취하고 있었다. 알려져 있는 고리상 펩티드인 cyclo-($Gln^1-Trp^2-Phe^3-Gly^4-Leu^5-Met^6$)의 Gly이 ${\beta}$Ala으로 바뀜에 따라 ${\beta}$Ala의 여분의 메틸렌이 고리의 골격의 반발력을 완화시키고 수소결합들이 형태의 안정에 기여하고 있다고 생각된다.

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NMR Techniques for the Structure Elucidation and Conformational Analysis of Natural Products

  • Cordell, Geoffrey A.
    • 생약학회지
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    • 제19권3호
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    • pp.153-169
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    • 1988
  • The combined use of the J-modulated selective INEPT and CSCM 1DNMR techniques is described for the structure elucidation of several new classes of compound including prionitin, the loureirins and larreantin, and for the regiosubstitution of the furanonaphthoquinones. Spectroscopic studies on the conformation of the cytotoxic agent savinin are also described, together with the NMR assignments and preliminary biosynthetic experiments on the antitumor antibiotic staurosporine.

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