• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1751-1757
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• 2007

Elastin-like polypeptides (ELPs) undergo a reversible inverse phase transition upon a change in temperature. This thermally triggered phase transition allows for a simple and rapid means of purifying a fusion protein. Recovery of ELPs-tagged fusion protein was easily achieved by aggregation, triggered either by raising temperature or by adding salt. In this study, levansucrase has been used as a model enzyme in the development of a simple one-step purification method using ELPs. The levansucrase gene cloned from Pseudomonas aurantiaca S-4380 was tagged with various sizes of ELPs to functionally express and optimize the purification of levansucrase. One of two ELPs, ELP[V-20] or ELP[V-40], was fused at the C-terminus of the levansucrase gene. A levansucrase-ELP fusion protein was expressed in Escherichia coli $DH5{\alpha}$ at $37^{\circ}C$ for 18 h. The molecular masses of levansucrase-ELP[V-20] and levansucrase-ELP[V-40] were determined as 56 kDa and 65 kDa, respectively. The phase transition of levansucrase-ELP[V-20] occurred at $20^{\circ}C$ in 50 mM Tris-Cl (pH 8) buffer with 3 M NaCl added, whereas the phase transition temperature ($T_t$) of levansucrase-ELP[V-40] was $17^{\circ}C$ with 2 M NaCl. Levansucrase was successfully purified using the phase transition characteristics of ELPs, with a recovery yield of higher than 80%, as verified by SDS-PAGE. The specific activity was measured spectrophotometrically to be 173 U/mg and 171 U/mg for levansucrase-ELP[V-20] and levansucrase-ELP[V-40], respectively, implying that the ELP-tagging system provides an efficient one-step separation method for protein purification.

• Journal of the Korean Chemical Society
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• v.48 no.5
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• pp.504-509
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• 2004

The reaction of Cu metal with mixed alkali metal polyselenide flux ($KNaSe_x$) produced large plate-like crystals of $KCu_4Se_3$. The structure of $KCu_4Se_3$, determined with X-ray single crystal diffraction techniques, is tetragonal (P4/mmm, a=4.013(1))${\AA}$, c=9.712(1))${\AA}$, z=1, R=6.7%). The structure is composed $[Cu_4Se_3]_n^{n-}$double layers which are made of fused anti PbO-type Cu2Se2 layers. Temperature variable resistivity measurement on single crystal of $KCu_4Se_3$ shows metallic behavior ranging from $1.8{\times}10^{-4}{\Omega}{\cdot}cm$ (at 300 K) to $1.0{\times}10^{-6}{\Omega}{\cdot}cm$ (at 20 K).

• Korea Science and Art Forum
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• v.29
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• pp.305-318
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• 2017

The need for recognizing the crime in the urban spaces as a social problem and finding out specific approaches such as the study of space design and various guidelines for crime prevention is increasing. In this regard, "Crime Prevention Through Environmental Design" (marked as "CPTED") is actively underway. Yeomri-dong Salt Way is the first place to which the Seoul Crime Prevention Design Project was appled. The business objective of improving the local environment has been implemented rationally through cooperation and voluntary participation between subject of the project executives and community members. Since its efficiency has been proven, the sites have been expanded since then and becomes a benchmarking example of each local government.This kind of problem solving effort has the same context in purpose and direction of the 'Village Art Project' which has been implemented since 2009 with the aim of promoting the culture of the underdeveloped area and encouraging the participation of the residents by introducing the public art. It is noteworthy that this trend is centered around the characteristics of community functions and values. The purpose of this study is to propose the application method of community furniture as a way to increase the efficiency of CPTED to improve the 'quality of life' of residents. To do this, we reviewed CPTED, community design, public art literature and prior research, and identified the problems and implications based on the site visit Yeomri-dong of Seoul and Gamcheon Village of Pusan which is the successful model of "Seoul Root out Crime by Design" and 'Maeulmisul Art Project' respectively. The common elements of the two case places identified in this study are as follows: First, the 'lives' of community residents found its place in the center through the activation of community by collaborative activities in addition to the physical composition of the environment. Second, community design and introduction of public art created a new space, and thereby many people came to visit the village and revitalize the local economy. Third, it strengthened the natural monitoring, the territoriality and control, and the activity increase among the CPTED factors. The psychological aspect of CPTED and the emotional function of public art are fused with the 'community furniture', thereby avoiding a vague or tremendous approach to the public space through a specific local context based on the way of thinking and emotion of local people and it will be possible to create an environment beneficial for all. In this way, the possibility and implication of the fusion of CPTED and public art are expected to be able to reduce the social cost through the construction of the crime prevention infrastructure such as expansion of the CPTED application space, and to suggest a plan to implement the visual amenity as a design strategy to regenerate city.