• 생명과학회지
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• 제8권2호
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• pp.223-233
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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.

• 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.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.59-63
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• 2003

The protein disulfide isomerase (PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody (Mab) refolding and assembly which accompanies disulfide bend formation. The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb in-termediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant fur a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.13-17
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• 1996

The protein disulfide isomerase(PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody(MAb) refolding and assembly which accompanies disulfide bond formation The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb intermediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant for a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1261-1267
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• 2003

We have investigated whether HspBP1, a Hsp70 binding protein, could have effect on the assembly of the bovine progesterone receptor (bPR) with a chaperone complex consisting of bovine Hsp90 (bHsp90), bovine Hsp70 (bHsp70), Hop, Ydj-1, and p23. The bPR, isolated in its native conformation, loses its function to interact with progesterone hormone in the absence of this protein complex. However, in the presence of bHsp90, bHsp70, Hop, p23 and Ydj-1, its function could be restored in vitro. Our findings here indicate that the inclusion of HspBP1 to five-protein system prevented the proper assembly of progesterone receptor-chaperone complex and induce the loss of bPR ability to interact with hormone. Immunoprecipitation assays of bPR with HspBP1 show that the presence of HspBP1 did not have any effect on the assembly of Ydj-1 and bHsp70 with the progesterone receptor. However, further assembly of Hsp90, Hop and p23 was completely prevented and the function of the bPR was lost. In vitro competition and protein folding assays indicated that the binding of HspBP1 to bHsp70 prevented the ternary complex formation of bHsp70, bHsp90, and Hop. These results indicate that HspBP1 is a negative regulator of the assembly of Hsp90, Hop and Hsp70, and thus, prevent the proper maturation of unliganded bPR with chaperones assembly system.

• 대한기계학회논문집A
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• 제30권7호
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• pp.841-848
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• 2006

Many researchers are developing computational prediction methods for protein tertiary structures to get much more information of protein. These methods are very attractive on the aspects of breaking technologies of computer hardware and simulation software. One of the computational methods for the prediction is a fragment assembly method which shows good ab initio predictions at several cases. There are many barriers, however, in conventional fragment assembly methods. Argues on protein energy functions and global optimization to predict the structures are in progress fer example. In this study, a new prediction method for protein structures is proposed. The proposed method mainly consists of two parts. The first one is a fragment assembly which uses very shot fragments of representative proteins and produces a prototype of a given sequence query of amino acids. The second one is a global optimization which folds the prototype and makes the only protein structure. The goodness of the proposed method is shown through numerical experiments.

• BMB Reports
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• 제32권3호
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• pp.311-316
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• 1999

Studies in adipocytes indicate that secretion of active lipoprotein lipase (LPL) was strictly regulated by a quality control system in the endoplasmic reticulum (ER). However, there has been no report about the ER chaperones participating in the folding and assembly of LPL. Many chaperones are known to bind unfolded proteins and dissociate from them through the ATP-hydrolyzing reaction. In this study, putative ER chaperones for LPL were determined by affinity chromatography using denatured LPL as an affinity ligand and elution with ATP. BiP, grp94, calreticulin, and another 50 kDa K-D-E-L protein in the ER of rat adipose tissue were bound to denatured LPL and eluted by ATP. Calnexin was bound to denatured LPL; however, it was not eluted by ATP but by acetic acid. These results indicate that, at least, BiP, grp94, calreticulin, calnexin, and the unidentified 50 kDa protein might act as putative chaperones for the proper folding and assembly of LPL in ER.

• 생명과학회지
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• 제16권3호
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• pp.409-414
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• 2006

소포체는 세포막의 합성뿐만 아니라 세포막에 존재하거나 세포외로 분비되어져야 할 단백질을 합성하는 세포내 소기관이다. 소포체에서 단백질이 합성되어질 경우 이황화결합이 형성되고 glycosylation 등의 수식이 일어나며, 이와 동시에 folding과 assembly과정을 거쳐 삼차원적 구조로 성숙이 되는데 이 과정은 folding enzyme과 molecular chaperone의 도움을 받아 이루어진다. 소포체 내에 존재하는 molecular chaperone 중 가장 잘 알려진 것으로 BiP이 있다. BiP의 기능은 N-terminus의 ATPase domain에 의해 조절되고 ATPase domain은 이것과 선택적으로 결합하는 조절인자에 의해 ATPase의 활성이 영향을 받는다. BiP의 핵산치환조절인자로서 발견된 BAP은 ATPase domain에 결합된 ADP를 ATP로 치환하는 것으로 기능이 알려져 있다. 이 BAP의 핵산치환기능이 BiP의 샤페론 작용에 어떤 영향을 미치는지를 in vitro에서 항체 heavy chain을 이용하여 알아보았다. BAP은 ATP보다 ADP가 결합되어 있는 BiP과 더 잘 결합을 하며, in vitro에서 BiP과 결합하고 있는 unfolded 단백질을 BAP은 BiP으로부터 해리하였다. 또한 소포체내에 존재하는 Hsp70 homologue chaperone인 BiP과 Grp170에 대한 BAP의 결합특이성을 anti-Grp170과 anti-BAP 항체로 co-immunoprecipitation을 하여 확인한 결과 BAP은 Grp170과 결합을 하지 않았다. 따라서 BAP은 ER내에 존재하는 동일한 family group에 속하는 Grp170과 BiP에 대하여 BiP에만 특이성을 갖는 것으로 나타났다.

• EDISON SW 활용 경진대회 논문집
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• 제3회(2014년)
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• pp.103-113
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• 2014

Hydrophobicity is the key concept to understand the role of water in protein folding, protein self-assembly, and protein-ligand interaction. Conventionally, hydrophobicity of amino acids in a protein has been argued based on hydrophobicity scales determined for individual free amino acids, assuming that those scales are unaltered when amino acids are embedded in a protein. Here, we investigate how the hydrophobicity of constituent amino acids depends on the protein context, in particular, on the total charge and secondary structures of a protein. To this end, we compute and analyze the hydration free energy - free energy change upon hydration quantifying the hydrophobicity - of three short proteins based on the integral-equation theory of liquids. We find that the hydration free energy of charged amino acids is significantly affected by the protein total charge and exhibits contrasting behavior depending on the protein net charge being positive or negative. We also observe that amino acids in the central ${\beta}$-strand sandwiched by ${\beta}$-sheets display more enhanced hydrophobicity than free amino acids, whereas those in the ${\alpha}$-helix do not clearly show such a tendency. Our results provide novel insights into the hydrophobicity of amino acids, and will be valuable for rationalizing and predicting the strength of water-mediated interaction involved in the biological activity of proteins.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.90-95
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• 2016

Heat Shock 70kDa Protein 1-Like(HSPA1L)는 Heat-shock protein70(HSP70) family에 속하는 chaperone protein으로 polypeptide folding, assembly, protein degradation 등 다양한 biological processes에 관여하고 있다. HSPA1L은 human methyltransferase-like protein 21A(METTL21A)에 의해 lysine residue에 methylation이 일어나게 되는데, 암세포에서 일반적인 HSPA1L은 주로 세포질에서 발견되는 반면 methylated HSPA1L의 경우 주로 핵에서 발견이 됨으로써 HSPA1L methylation이 암 세포 성장에 중요할 역할을 할 것이라 추측되며 anti-cancer drug target으로 주목 받고 있다. 하지만 현재 HSPA1L의 구조가 부분적으로만 밝혀져 있어 HSPA1L와 METTL21A가 어떤 residue들이 interaction 하여 binding을 하는지에 대해서 아직 밝혀 지지 않았다. 이로 인해 anti-cancer drug target으로서의 연구에 제한이 있다. 이번 연구에서는 homology modeling(Galaxy-TBM, Galaxy-refine)을 통해 HSPA1L 전체 구조를 밝혀 낸 후, HSPA1L 와 METTL21A를 protein-protein docking을 통해 binding pose 예측을 하였다. 이러한 binding pose를 protein interaction analysis하여 HSPA1L과 METTL21A binding에 관여하는 중요 residue들을 밝혀 냈다. 이러한 structural information은 methylated HSPA1L와 암 세포 성장간의 연관성, 더 나아가 anti-cancer drug 개발로 까지도 이어 질 수 있을 것이라 생각한다.