• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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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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• v.29 no.11
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• pp.2195-2201
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• 2008

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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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.

• Journal of ILASS-Korea
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• v.13 no.1
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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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• v.33 no.2
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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.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.1-11
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• 2003

Acoording to improvement of HTOS (high throughput organic synthesis) and HTS (high throughput screening) technique, the CoMFA (comparative molecular field analysis), CoMSIA (comparative molecular similarity indeces analysis) and molecular HQSAR (hologram quantitative structure-activity relationship) analysis techniques as methodology of computer assisted molecular design (CAMD) were introduced generally and summarized for some application cases.

• BMB Reports
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• v.40 no.1
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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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• v.32 no.2
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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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• v.58 no.2
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• pp.230-234
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• 2020

A system that uses deep-learning techniques to predict properties from molecular structures has been developed to apply to chemical, biological and material studies. Based on the database where molecular structure and property information are accumulated, a deep-learning model looking for the relationship between the structure and the property can eventually provide a property prediction for the new molecular structure. In addition, experiments on the actual properties of the selected molecular structure will be carried out in parallel to carry out continuous verification and model updates. This allows for the screening of high-quality molecular structures from large quantities of molecular structures within a short period of time, and increases the efficiency and success rate of research. In this paper, we would like to introduce the overall composition of the materiality prediction system using deep-learning and the cases applied in the actual excavation of new structures in LG Chem.