• 한국결정학회:학술대회논문집
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• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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• pp.24-24
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• 2002

HtrA (high temperature requirement A), a periplasmic heat shock protein, is known to have molecular chaperone function at low temperatures and proteolytic activity at elevated temperatures. To investigate the mechanism of functional switch to pretense, we have determined the crystal structure of the N-terminal protease domain (PD) of HtrA from Thermotoga maritima. HtrA PD shares the same fold with chymotrypsin-like serine professes. However, crystal structure suggests that HtrA PD is not an active pretense at current state since its active site is not formed properly and blocked by an additional helical lid. On the surface of the lid, HtrA PD has hydrophobic patches that could be potential substrate binding sites for molecular chaperone activity. Present structure suggests that the activation of the proteolytic function of HtrA PD at elevated temperatures might occur by the conformational change.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.232-234
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• 1996

We have investigated the effect of molecular structure of polymer of rubbed polyimide (PI) films for surface liquid crystal alignment. To obtain surface alignment effect of Polymer molecular structure, we measured the polar (out of plane-tilt) anchoring strength and surface ordering of 5CB on rubbed PI surfaces. We have found that the polar anchoring strength of 5CB is depend on the polymer molecular structure of these unidirectionally rubbed PI surfaces.

• Bulletin of the Korean Chemical Society
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• 제29권11호
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• pp.2195-2201
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• 2008

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.656-659
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• 2005

Small peptides synthesized by nonribosomal peptide synthetases (NRPSs) genes are found in bacteria and fungi. While some microbial taxa have few, others make a large number and variety. However, biochemical characterization of the products synthesized by NPRS demands a great deal of efforts. Since the completion of genome projects of numerous microorganisms, the numbers of available NRPSs genes are being expanded. Prediction of the peptides encoded by NRPS could save time and efforts. We chose the NRPS gene from Bradyrhizobium japonicum as a model to predict the peptide structure encoded by NRPS genes. Using computational analyses, the domain structure of this gene was defined, and the structure of a peptide synthesized by this NRPS was deduced. It was found that it encoded a tripeptide consisting of proline-serine-phenylalanine. This method would be helpful to predict the structure of small peptides with various NPRS genes from the genome sequence.

• 한국분무공학회지
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• 제13권1호
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• pp.34-41
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• 2008

Molecular dynamic simulations have been carried out to study the effect of the nano-structure substrate and its temperature on cluster laminating. The interaction between substrate molecules and liquid molecules was modeled in the molecular scale and simulated by the molecular dynamics method in order to understand behaviors of the liquid cluster on nano-structure substrate. In the present model, the Lennard-Jones potential is applied to mono-atomic molecules of argon as liquid and platinum as nano-structure substrate to perform simulations of molecular dynamics. The effect of wettability on a substrate was investigated for the various beta of Lennard-Jones potential. The behavior of the liquid cluster and nano-structure substrate depends on interface wettability and function of molecules force, such as attraction and repulsion, in the collision progress. Furthermore, nano-structure substrate temperature and beta of Lennard-Jones potential have effect on the accumulation ratio. These results of simulation will be the foundation of coating application technology for micro fabrication manufacturing.

• BMB Reports
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• 제33권2호
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• pp.133-137
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• 2000

To elucidate the effect of oxygen radicals on the molecular properties of proteins, the secondary and tertiary structure and molecular weight size of BSA and ${\beta}$-lactoglobulin were examined after irradiation of proteins at various doses. Gamma-irradiation of protein solutions caused the disruption of the ordered structure of protein molecules as well as degradation, cross-linking, and aggregation of the polypeptide chains. As a model system, BSA and ${\beta}$-lactoglobulin were used as a typical ${\alpha}$-helical and a ${\beta}$-sheet structure protein, respectively. A circular dichroism study showed that the increase of radiation decreased the ordered structure of proteins with a concurrent increase of aperiodic structure content. Fluorescence spectroscopy indicated that irradiation quenched the emission intensity excited at 280 nm. SDS-PAGE and a gel permeation chromatography study indicated that radiation caused initial fragmentation of proteins resulting in a subsequent aggregation due to cross-linking of protein molecules.

• 농약과학회지
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• 제7권1호
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• pp.1-11
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• 2003

새로운 농약을 탐색하고 개발하는데 있어서 고효율 유기함성 (HTOS) 기술과 고효율 검색 (HTS) 기술 등의 발전과 더불어 컴퓨터 화학을 이용한 분자설계 (CAMD) 방법으로 보편화되고 있는 비교 분자장 분석(CoMFA)과 비교 분자 유사성 지수분석(CoMSIA) 등, 3D QSAR 기법들을 위시하여 분자 홀로그램 구조 - 활성관계 (HQSAR) 분석방법 등, QSAR 기법들을 요약하고 그 활용 사례들을 간략하게 소개하였다.

• BMB Reports
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• 제40권1호
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• pp.58-64
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• 2007

Similar to the other known structures of Bacillus thuringiensis Cry $\delta$-endotoxins, the crystal structure of the 65-kDa activated Cry4Ba toxin comprises three domains which are, from the N- to C-terminus, a bundle of $\alpha$-helices, a three-$\beta$-sheet domain, and a $\beta$-sandwich. To investigate the properties of the C-terminal domain III in isolation from the rest of the toxin, the cloned Cry4Ba-domain III was over-expressed as a 21-kDa soluble protein in Escherichia coli, which cross-reacted with anti-Cry4Ba domain III monoclonal antibody. A highly-purified domain III was obtained in a monomeric form by ion-exchange and size-exclusion FPLC. Circular dichroism spectroscopy indicated that the isolated domain III fragment distinctly exists as a $\beta$-sheet structure, corresponding to the domain III structure embodied in the Cry4Ba crystal structure. In vitro binding analysis via immuno-histochemical assay revealed that the Cry4Ba-domain III protein was able to bind to the apical microvilli of the susceptible Stegomyia aegypti larval midguts, albeit at lower-binding activity when compared with the full-length active toxin. These results demonstrate for the first time that the C-terminal domain III of the Cry4Ba mosquito-larvicidal protein, which can be isolated as a native folded monomer, conceivably participates in toxin-receptor recognition.

• ALGAE
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• 제32권2호
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• pp.87-100
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• 2017

The genera Hypnea and Calliblepharis of the family Cystocloniaceae are discriminated by their female reproductive structure, especially in the formation of carposporangia and gonimoblasts. Hypnea saidana, once classified based on obsolete evidence, has not been studied phylogenetically using molecular analysis and detailed reproductive structure though it shares many morphologic features with the genus Calliblepharis. To provide better understanding of generic relationship of H. saidana with Hypnea and Calliblepharis, we carried out molecular analyses using the nuclear-encoded small subunit ribosomal DNA (SSU) and chloroplast-encoded large subunit of the RuBisCO (rbcL), and exact morphological observations focusing on the reproductive structures of wild specimens. Our molecular phylogeny showed that H. saidana is closely related to Calliblepharis, but distinct from the clade of Hypnea. Female reproductive structure of H. saidana characterized by upwardly developing chains of carposporangia, central reticulum of cell, and gonimoblast filaments not connected to the pericarp provides definite evidence to assign the taxonomic position of this species to Calliblepharis. Based on our combined molecular and morphological analyses, we have proposed Calliblepharis saidana comb. nov., expanding the distribution of Calliblepharis habitat from the eastern Atlantic South Africa, the northern Indian Ocean, Australasia, and Brazil to the western Pacific Ocean.

• Korean Chemical Engineering Research
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• 제58권2호
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• pp.230-234
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• 2020

딥러닝 기법을 활용하여 분자 구조로부터 물성을 예측하는 시스템은 화학, 생물학, 재료 연구에 적용하기 위해 개발되었다. 분자 구조와 물성 정보가 축적된 데이터베이스를 기반으로, 구조와 물성간의 관계식을 찾는 딥러닝 모형을 구축한 후 최종적으로는 새로운 분자 구조에 대한 물성 예측값을 제공할 수 있다. 또한 선정된 분자 구조의 실제 물성값에 대한 실험을 병행하여 지속적인 검증 및 모형 업데이트를 수행하게 된다. 이를 통해 다량의 분자구조로부터 물성이 우수한 분자 구조를 빠른 시간 안에 스크리닝할 수 있으며, 연구의 효율성 및 성공률을 높일 수 있다. 본 논문에서는 딥러닝을 활용한 물성 예측 시스템의 전반적인 구성과 LG화학에서 실제 신규 구조 발굴에 적용된 사례를 중심으로 소개하고자 한다.