• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.303-305
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• 2003

In this paper, we have been proposed a new method of multichannel biosensor using random fluidic self-assembly. A metal particle and an array was fabricated. Biomaterials were immobilized on the metal particle. The array and the particles were mixed in a buffer solution, and were arranged by self-assembly. A quarter of total Ni dots were covered by the particles. The binding direction of the particles was controllable, and condition of particles was almost with Au surface on top. The particles were successfully arranged on the array. The biomaterial activities were detected by chemiluminescence.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2398-2400
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• 2005

In this paper, we have been described a new constructing method of multichannel biosensor using self-assembly by magnetic force interaction. A metal particle and an array was fabricated by photolithographic. Biomaterials were immobilized on the metal particle. The array and the particles were mixed in a buffer solution, and were arranged by magnetic force interaction and self-assembly. A quarter of total Ni dots were covered by the particles. The binding direction of the particles was controllable, and condition of particles was almost with Au surface on top. The particles were successfully arranged on the array. The biomaterial activities were detected by chemiluminescence.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1317-1318
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• 2006

In this paper, we have been described a new constructing method of multichannel biosensor using self-assembly by magnetic force interaction. A metal particle and an array was fabricated by photolithographic. Biomaterials were immobilized on the metal particle. The array and the particles were mixed in a buffer solution, and were arranged by magnetic force interaction and self-assembly. A quarter of total Ni dots were covered by the particles. The binding direction of the particles was controllable, and condition of particles was almost with Au surface on top. The particles were successfully arranged on the array. The biomaterial activities were detected by chemiluminescence.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.386-387
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• 2006

This research describes a new constructing method of multifunctional biosensor using many kinds of biomaterials. A metal particle and an array was fabricated by photolithographic. Biomaterials were immobilized on the metal particle. The array and the particles were mixed in a buffer solution, and were arranged by magnetic force interaction and self-assembly. A quarter of total Ni dots were covered by the particles. The binding direction of the particles was controllable, and condition of particles was almost with Au surface on top. The particles were successfully arranged on the array. The biomaterial activities were detected by chemiluminescence and electrochemical methods.

• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.336-341
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• 1993

In metal-affinify aqueous two-phase systems, protein partitioning is affected by a variety of parameters such as pH, the number of surface-accessible histidines, and the amount and partition coefficient of metallated polythylene glyco(PEG) ligand. To enhance partitioning of proteins with surface-accessible histidines, we have synthesized and used a (Cu(II)-ininodiacetic acid)$_2$-PEG20,000($Cu(II)_2IDA_2$-PEG20,000) as well as Cu(II)IDA-PEG5,000 as an affinity ligand. The partition coefficient of $Cu(II)_2-IDA_2$-PEG20,000 in a PEG5,000/dextran two-phase system was 30.1, which corresponded to a 3.8-fold increase over that of Cu(II)IDA-PEG5,000. The partitioning experiments were performed on four proteins, horse cytochrome c, S. cerevisiae cytochrome c, horse myoglobin, and sheep myoglobin. Partitioning of proteins which convey surface-accessible histidines was enhanced dramatically by the addition of $Cu(II)_2IDA_2$-PEG20,000 ligand. These results demonstrate that enhanced partitioning of metal-binding proteins in an aqueous two -phase system can by achieved by using an appropriate metallated PEG ligand.

• BMB Reports
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• v.43 no.5
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• pp.319-324
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• 2010

Experimental bioinformatics data obtained from an E. coli cell-based eukaryotic protein purification experiment were analyzed in order to identify any bottleneck as well as the factors affecting the target purification. All targets were expressed as His-tagged maltose-binding protein (MBP) fusion constructs and were initially purified by immobilized metal affinity chromatography (IMAC). The targets were subsequently separated from the His-tagged MBP through TEV protease cleavage followed by a second IMAC isolation. Of the 743 total purification trials, 342 yielded more than 3 mg of target proteins for structural studies. The major reason for failure of target purification was poor TEV proteolysis. The overall success rate for target purification decreased linearly as cysteine content or isoelectric point (pI) of the target increased. This pattern of pI versus overall success rate strongly suggests that pI should be incorporated into target scoring criteria with a threshold value.

• Mass Spectrometry Letters
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• v.9 no.1
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• pp.17-23
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• 2018

Studies on the interactions of amyloidogenic proteins with trace metals, such as copper, have indicated that the metal ions perform a critical function in the early oligomerization process. Herein, we investigate the effects of Cu(II) ions on the active sequence regions of amyloidogenic proteins using electrospray ionization mass spectrometry (ESI-MS) and collision induced dissociation tandem MS (CID-MS/MS). We chose three amyloidogenic peptides NNQQNY, LYQLEN, and VQIVYK from yeast prion like protein Sup35, insulin chain A, and tau protein, respectively. [Cu-peptide] complexes for all three peptides were observed in the mass spectra. The mass spectra also show that increasing Cu(II) concentrations decrease the population of existing peptide oligomers. The tandem mass spectrum of NNQQNY shows preferential binding for the N-terminal region. All three peptides are likely to appear to be in a Cu-monomer-monomer (Cu-M-M) structure instead of a monomer-Cu-monomer (M-Cu-M) structure.

• Korean Journal of Microbiology
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• v.48 no.3
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• pp.187-191
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• 2012

Two-component system (TCS)-based bacterial zinc and copper biosensors, in which green fluorescent protein (GFP) is expressed under the control of zraP and cusC promoter in ZraS/R and CusS/R TCS, were evaluated in artificial wastewater. Bacterial biosensors developed in this study efficiently expressed GFP by the recognition of $Zn^{2+}$ and $Cu^{2+}$ in artificial wastewater. Secondly, TCS-based zinc and copper removing bacteria with the peptide displayed on cell surface were examined in artificial wastewater. Zinc and copper removing bacteria expressed the peptide as a fusion protein such as OmpC-ZBP (zinc binding peptide) and OmpC-CBP (copper binding peptide) on the cell surface when sensing exogenous $Zn^{2+}$ and $Cu^{2+}$ through ZraS/R and CusS/R TCS. The recombinant cell expressing metal-adsorbing peptide could efficiently remove copper and zinc (15 and 18 mg/g dry cell weight, respectively) in artificial wastewater. Therefore, it was demonstrated that the TCS-based recombinant cell for the recognition or removal of heavy metal functions well in artificial wastewater environment.

• Applied Microscopy
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• v.29 no.3
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• pp.323-329
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• 1999

Synthesis of inorganic nanophase particles was performed to verify and understand the binding of non-ferrous metal ions including Al and $UO_2$ to the apoferritin molecules. Reconstituted inorganic particles of Al or $UO_2$ were identified by TEM as discrete electron dense cores encapsulated within the protein shell. The corresponding EDXA spectra confirm the presence of metal ions in the reconstituted ferritin. The Al cores of ferritin has been studied by TEM for the first time. Bimetallic cores with Al/Fe and $UO_2/Al$ were also produced and examined under TEM. Mixed metal cores encapsulated in the protein shell are well formed and its corresponding EDXA spectra also confirm the presence of metal ions in the mineral cores. Therefore, the present study proves that ferritin can be used to synthesize inorganic nanophase particles of Al and $UO_2$.

• KSBB Journal
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• v.9 no.3
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• pp.279-286
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• 1994

A mathematical model has been derived and used to describe phosphoprotein partitioning in Fe(III) IDA-PEG/dextran two-phase systems. This model includes the inhibitory effects of hydrogen and hydroxyl ion concentrations on protein partitioning. For aqueous two-phase partitioning experiments, the Al and A2 subcomponents of ovalbumin carrying two and one surface phosphoryl group(s) were purified using an immobilized metal ion affinity chromatography (IMAC). The ratio of partition coefficients in the presence and absence of Fe(III)IDA-PEG, K/Ko, increased in the pH range of 3.0 to 5.0 due to deprotonation of the second oxygen of the phosphoryl group, and above pH 5.0 declined steeply by the inhibitory binding of hydroxyl ions to the metal ion. This partitioning behavior was well described by the mathematical model. The binding constants for formation of the complex between the phosphoryl group and the Fe(III)IDA-PEG were found to be $6.1{\times}10^3M^{-1} and 2.3{\times}10^4M^{-1}$ in the top and bottom phases, respectively. These values are 3-5 times those for interaction of Cu(II)IDA-PEG with a single surface-accessible histidine.