• BMB Reports
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• 제45권4호
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• pp.239-241
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• 2012

Iron availability is limited in the environment and most bacteria have developed a system to acquire iron from host hemoproteins. Heme oxygenase plays an important role by degrading heme group and releasing the essential nutrient iron. The structure of Bacillus subtilis HmoB was determined to 2.0 ${\AA}$ resolution. B. subtilis HmoB contains a typical antibiotic biosynthesis monooxygenase (ABM) domain that spans from 71 to 146 residues and belongs to the IsdG family heme oxygenases. Comparison of HmoB and IsdG family proteins showed that the C-terminal region of HmoB has similar sequence and structure to IsdG family proteins and contains conserved critical residues for heme degradation. However, HmoB is distinct from other IsdG family proteins in that HmoB is about 60 amino acids longer in the N-terminus and does not form a dimer whereas previously studied IsdG family heme oxygenases form functional homodimers. Interestingly, the structure of monomeric HmoB resembles the dimeric structure of IsdG family proteins. Hence, B. subtilis HmoB is a heme oxygenase with a novel structural feature.

• 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.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4041-4046
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• 2012

The recombinant expression of proteins has been the method of choice to meet the demands from proteomics and structural genomics studies. Despite its successful production of many heterologous proteins, Escherichia coli failed to produce many other proteins in their native forms. This may be related to the fact that the stresses resulting from the overproduction interfere with cellular processes. To better understand the physiological change during the overproduction phase, we profiled the metabolites along the time course of the recombinant protein expression. We identified 32 metabolites collected from different time points in the protein production phase. The stress induced by protein production can be characterized by (A) the increased usage of aspartic acid, choline, glycerol, and N-acetyllysine; and (B) the accumulation of adenosine, alanine, oxidized glutathione, glycine, N-acetylputrescine, and uracil. We envision that this work can be used to create a strategy for the production of usable proteins in large quantities.

• Bulletin of the Korean Chemical Society
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• 제20권10호
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• pp.1159-1164
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• 1999

The study investigated the effect of carrier composition (ionic strength and pH) on the retention of various proteins in flow field-flow fractionation (Flow FFF) as well as the conformational change of Bovine Serum Albumin (BSA) with urea concentration, storage time and temperature. The study found that the retention of protein in Flow FFF increased with the ionic strength of the carrier liquid. Most proteins were well solubilized at pH = 7-8. The hydrodynamic diameters obtained from Flow FFF retention data agree well with theoretical values. The retention increased and the peak shape became distorted at extreme pH conditions of the carrier solution. The selected carrier composition for comparison between the literature value of proteins was 0.05 M tris buffer solution with a pH of 8. Storing BSA at 4 ±2℃ over a period of three months resulted in slow dimerization. Also, in case of the storage of BSA at 37 ±5℃ for one week, the retention of both BSA monomer and dimer increased with the urea concentration. Finally, the structural composition of specific enzymes: malonyl-CoA decarboxylase (MCDC) and malonyl-CoA synthesis (MCS) was determined by using Flow FFF at specific carrier solutions. The molecular weight of the natural MCDC was determined to be 208 kDa, which means it is a homotetramer, while that of the MCS was determined to be 47 kDa, which means it is a monomer.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.275.1-275.1
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• 2002

It has been proposed that G protein interacts with receptor via multiple interaction sites. With regard to this, C-terminus of the G${\alpha}$ subunit is clearly not the only structural determinant on the G proteins that is critical for receptor coupling selectivity, but the extreme N-terminus of Ga subunit and other structural elements were proposed to be responsible for dictating the interaction with receptors. (omitted)

• 한국자기공명학회논문지
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• 제13권1호
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• pp.15-26
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• 2009

The NMR detection of methyl groups is of keen interest because they provide the long-range distance information required to establish global folds of high molecular weight proteins. Using longitudinal $^1H$ relaxation optimization, we achieve a gain in sensitivity of approximately 1.6-fold in the methyl-TROSY and its NOESY experiments for the 38 kDa protein mitogen activated protein kinase p38 in its fully protonated and $^{13}C$ and $^{15}N$ labeled state.

• BMB Reports
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• 제50권5호
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• pp.237-246
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• 2017

Synapse is the basic structural and functional component for neural communication in the brain. The presynaptic terminal is the structural and functionally essential area that initiates communication and maintains the continuous functional neural information flow. It contains synaptic vesicles (SV) filled with neurotransmitters, an active zone for release, and numerous proteins for SV fusion and retrieval. The structural and functional synaptic plasticity is a representative characteristic; however, it is highly vulnerable to various pathological conditions. In fact, synaptic alteration is thought to be central to neural disease processes. In particular, the alteration of the structural and functional phenotype of the presynaptic terminal is a highly significant evidence for neural diseases. In this review, we specifically describe structural and functional alteration of nerve terminals in several neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD).

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.81.2-82
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• 2003

Plants have evolved along with pathogens, and they have developed sophisticated defense systems against specific microorganisms to survive. G-protons are considered one of the upstream signaling components working as a key for the defense signal transduction pathway. For activation and inactivation of G-protein, GTP-biding proteins are involved. GTP -binding proteins are found in all organisms. Small GTP-binding proteins, having masses of 21 to 30kD, belong to a superfamily, often named the Ras supefamily because the founding members are encoded by human Ras genes initially discovered as cellular homologs of the viral ras oncogene. Members of this supefamily share several common structural features, including several guanine nucleotide binding domains and an effector binding domain. However, exhibiting a remarkable diversity in both structure and function. They are important molecular switches that cycle between the GDP-bound inactive form into the GTP-bound active form through GDP/GTP replacement. In addition, most GTP-binding proteins cycle between membrane-bound and cytosolic forms. such as the RAC family are cytosolic signal transduction proteins that often are involved in processing of extracellular stimuli. Plant RAC proteins are implicated in regulation of plant cell architecture secondary wall formation, meristem signaling, and defense against pathogens. But their molecular mechanisms and functions are not well known. We isolated a RacB homolog from rice to study its role of defense against pathogens. We introduced the constitutively active and the dominant negative forms of the GTP-hinging protein OsRacB into the wild type rice. The dominant negative foms are using two forms (full-sequence and specific RNA interference with RacB). Employing southern, and protein analysis, we examine to different things between the wild type and the transformed plant. And analyzing biolistic bombardment of onion epidermal cell with GFP-RacB fusion protein revealed association with the nucle.

• 대한의생명과학회지
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• 제6권3호
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• pp.171-179
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• 2000

대부분 척추동물에서 골격근 내 filament들의 길이 조절은 근 수축 기작의 구조를 이해하는데 중요한 단서가 된다. Nebulin은 thin filament의 전체에 걸쳐있는 거대한 단백질로 골격근에만 특이적으로 존재하는 것으로 알려져 왔다. 본 연구에서는 닭의 근육과 비근육 조직에서 nebulin isoform단백질들을 확인하기 위하여 전기영동과 immunoblot의 방법을 이용하였다. 각 조직의 단백질들은 soluble과 insoluble fraction으로 분리 준비하였다. 실험결과, 닭의 근육과 비근육 조직들에서 조직 특이성을 나타내는 다양한 nebulin isoform 단백질들이 확인되었다. Nebulin은 성계의 골격근에서 500 kDa 정도의 크기로 나타났고, nebulett은 계배와 성계의 심장근에서 107 kDa 정도로 발현되었다. 그리고 계배의 비근육 조직인 뇌에서 380 kDa 정도의 거대 단백질이 확인되었다. 이 단백질은 뇌 조직의 soluble fraction에서 인지되었다. Nebulin isoform 단백질들이 서로 다른 조직에서 발현되는 양상을 보아 서로 다른 독자적인 기능을 가질 것으로 추정된다.

• 한국환경농학회지
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• 제37권4호
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• pp.324-332
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• 2018

곤충은 변온동물로 육지생태계에서 주로 서식하면서, 식물의 생체량 조절, 종다양성 유지에 중요한 역할을 한다. 주변온도는 변온동물인 곤충의 생리적 반응속도, 뿐만 아니라 생존과 분포를 결정하며, 기후변화에 영향을 준다. 본 연구는 높은 온도에서 곤충의 적응성에 관련있는 유전자를 전사체를 이용하여 동정하였다. 고온에서 사육된 배추좀나방 유충의 지방체로부터 차세대 염기서열 분석법을 이용하여 전사체를 확보하였다. 대사중심인 지방체에서 구조단백질, 열충격단백질, 항산화단백질, 해독효소 들이 동정되었다. 이들 중에서 표피단백질(표피단백질, 키틴합성효소, 엑틴, 카이틴 합성), 스트레스관련단백질(시토크롬 P450), 열충격단백질, 한산화단백질은 발현이 증가되었으나, glutathione S transferase 발현은 오히려 감소되었다. 이상의 결과는 기후변화의 주요인인 온난화에 대한 해충의 생리적 대응과 온도적응을 이해하는데 필요한 기초자료를 제시한다.