• 제목/요약/키워드: protein folding

검색결과 228건 처리시간 0.028초

Characterization of nucleotide-induced changes on the quaternary structure of human 70 kDa heat shock protein Hsp70.1 by analytical ultracentrifugation

  • Borges, Julio C.;Ramos, Carlos H.I.
    • BMB Reports
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    • 제42권3호
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    • pp.166-171
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    • 2009
  • Hsp70s assist in the process of protein folding through nucleotide-controlled cycles of substrate binding and release by alternating from an ATP-bound state in which the affinity for substrate is low to an ADP-bound state in which the affinity for substrate is high. It has been long recognized that the two-domain structure of Hsp70 is critical for these regulated interactions. Therefore, it is important to obtain information about conformational changes in the relative positions of Hsp70 domains caused by nucleotide binding. In this study, analytical ultracentrifugation and dynamic light scattering were used to evaluate the effect of ADP and ATP binding on the conformation of the human stress-induced Hsp70.1 protein. The results of these experiments showed that ATP had a larger effect on the conformation of Hsp70 than ADP. In agreement with previous biochemical experiments, our results suggest that conformational changes caused by nucleotide binding are a consequence of the movement in position of both nucleotide- and substrate-binding domains.

Refolding of Acid-Unfolded Globin to Hemoglobin

  • 이종우
    • 대한의생명과학회지
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    • 제11권1호
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    • pp.85-88
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    • 2005
  • Hemoglobin is oxygen carrier protein within erythrocyte in blood. Apoprotein of this, globin, is synthesized in the cytosol but it's cofactor, heme, is synthesized in the mitochondria. It has not been known very well how globin receives the heme from mitochondria and folds to hemoglobin. In this folding process, the initial structure of globin seems to be very important. A small volume of globin at acid pH was added rapidly into the bulk of an egg phosphatidylcholine $60\%$ liposome, containing hemins, at neutral pH according to the Rapid Dilution method. It was observed that an acid-induced unfolding structure of globin is initially needed to receive hemins from the lipid bilayer of liposomes. Also, this conclusion was confirmed with the absorption spectrum of the refolded globin separated by centrifugation.

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Conformational Studies of Gaseous Proteins Using Mass Spectrometry

  • Oh, Han-Bin
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.27-27
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    • 2003
  • Conformations of the +5 to +13 charge state of ubiquitin ions have been studied in the gas phase by an Electron Capture Dissociation (ECD) mass spectrometry (MS) technique. This approach has showed that the conformations of the gaseous ions change from the compact to extended structures as the number of protons on the protein ions increases, consistent with previous collisional cross-section measurements by an ion-mobility MS. However, this observation is in contrast to that of the solution-phase where the unique native structure is usually found. The (un)folding stability and kinetics of these gaseous ions were further investigated experimentally using gradual blackbody-radiation or sudden laser-induced thermal heating, respectively. These studies have provided the evidence that the thermodynamics and kinetics of protein (un)folding in the gas phase are quite different from those of the native aqueous proteins.

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Structure Analysis of the Full Length PDI Genomic DNA Isolated from Bombyx mori

  • Kim, Sung-Wan;Goo, Tae-Won;Yun, Eun-Young;Park, Kwang-Ho;Hwang, Jae-Sam;Kang, Seok-Woo;Kwon, O-Yu
    • 한국잠사학회:학술대회논문집
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    • 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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    • pp.44-44
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    • 2003
  • Protein disulfide isomerase (PDI) is not only an isomerase catalyzing the formation of native disulfide bond(s) of nascent peptide, but also a molecular chaperone assisting chain folding. We have already reported the structure of a cDNA (bPDl) encoding PDI from Bombyx mori and the function of PDI as foldase in assisting protein folding. (omitted)

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24번 잔기가 치환된 트립토판 중합효소 $\alpha$ 소단위체들의 구조풀림 성질 (Unfolding Property of Residue 24-Substituted Tryptophan Synthase $\alpha$-Subunits)

  • 정지은;박후휘;신혜자;임운기
    • 생명과학회지
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    • 제9권6호
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    • pp.733-736
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    • 1999
  • 대장균 트립토판 중합요소 (tryptophan synthase) $\alpha$ 소단위체의 24번 잔기인 트레오닌이 메티오닌, 알라닌 또는 세린으로 치환되고 잔기 139에 트립토판이 있는 단백질를 정제하여, 여러가지 요소 농도에 대한 트립토판 형광값의 변화를 측정하여 변성곡선을 얻었다. 이들 단백질들은 모두 F139W 단백질에 비해 구조형성 성질에 큰 변화를 일으켰으며, 잔기 24번은 구조형성에 중요한 것으로 추정된다.

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Mini-proinsulins with a beta-turn motif

  • Chang, Seung-Gu;Kim, Dae-Young;Kim, Young-Sook;Park, Ki-Doo;Shin, Jae-Min;Shin, Hang-Cheol
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1995년도 제3회 추계심포지움
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    • pp.41-48
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    • 1995
  • To increase the folding efficiency of proinsulin, we have designed a series of mini-proinsulins having the central C-peptide region replaced with sequences forming reverse turns. These proteins were produced as fusion proteins in E. coli in the form of inclusion bodies. After isolation process of the sulfonated mini-proinsulins, the subsequent refolding experiments indicate that the mini-proinsulins, with non-native penta-peptide sequences inserted between two of the enzyme processing sites, show substantially increased folding yields compared with the proinsulin. The correct disulfide connections were verified by fingerprint analysis using Glu-C endoproteinase. These novel mini-proinsulins could be used for the study of folding mechanism of proinsulin.

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FOLDING-UNFOLDING KINETICS OF HUMAN $\alpha_1$-ANTITRYPSIN: CHARACTERIZATION OF A KINETIC INTERMEDIATE THAT IS BRANCHED TO THE NATIVE AND AGGREGATION FORM

  • Kim, Daeyou;Yu, Myeong-Hee
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1996년도 정기총회 및 학술발표회
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    • pp.13-13
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    • 1996
  • Aggregation of human $\alpha$$_1$-antitrypsin ($\alpha$$_1$-AT) during folding occurs both in vitro and in vivo. In vivo aggregates of mutant $\alpha$$_1$-AT such as $M_{malton}$ (Phe52 deleted) and Z (Glu342 longrightarrowLys) variants have pathological consequences. In order to analyze the process of $\alpha$$_1$-AT aggregation in detail, the folding-unfolding kinetics of $\alpha$$_1$-AT was examined by monitoring intrinsic Trp fluorescence and ANS binding. (omitted)

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세포내인자로서의 정교한 기능을 하는 molecular chaperone (Molecular chaperone as a sophisticated intracellular membership)

  • 권오유;송민호
    • 생명과학회지
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    • 제8권2호
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    • pp.226-226
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    • 1998
  • Molecular chaperone의 발견은 생명과학자들에게 살아있는 세포 내에서 어떻게 생체활성단백질이 만들어지고 유지되는지에 대한 자극과 함께 그것을 증명하기 위한 실험동기를 부여하였다. 초기에는 Molecular chaperone이 nucleosomes의 assembly에 관여하는 단백질을 설명하기 위하여 사용되었으나, 지금은 기본적인 세포생리기능의 하나인 단백질의 folding과 assembly를 돕는 assistant protein으로 주로 사용된다. 단백질합성 뿐만 아니라 단백질수송, oligomeric structure의 assembly와 disassembly, heat shock을 포함한 각종 내, 외부스트래스에 의해서 변성된 단백질의 세로내분화와 회복에도 Molecular chaperone이 관여하고 있다. 그러나 아직까지는 Molecular chaperone들의 3차구조와 그들간의 상호작용에 관한 정보가 부족하여 크게 진전되지 못하고 있지만, 많은 연구자에 의한 정보축적으로 인하여 빠른 시일 내에 Molecular chaperone에 세포내역할이 분명하게밝혀질 것이다.