• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1997년도 학술발표회
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• pp.44-44
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• 1997

Ca$^{2＋}$ is one of the most common metal ions associated with proteins, playing more or less well-defined functional roles in biological activities. In protease, the presence of $Ca^{2＋}$ slows down autolysis and enhances thermal stability. Subtilisin, one of the best studied proteases, is known to have two $Ca^{2＋}$ -binding sites.(omitted)

• 한국자기공명학회논문지
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• 제19권3호
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• pp.112-118
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• 2015

Hsp31 protein is one of the members of DJ-1 superfamily proteins and has a dimeric structure of which molecular weight (MW) is 62 kDa. The mutation of DJ-1 is closely related to early onset of Parkinson's disease. Hsp31 displays $Zn^{+2}$-binding activity and was first reported to be a holding chaperone in E. coli. Its additional glyoxalase III active has recently been characterized. Moreover, an incubation at $60^{\circ}C$ induces Hsp31 protein to form a high MW oligomer (HMW) in vitro, which accomplishes an elevated holding chaperone activity. The NMR technique is elegant method to probe any local or global structural change of a protein in responses to environmental stresses (heat, pH, and metal). Although the presence of the backbone chemical shifts (bbCSs) is a prerequisite for detailed NMR analyses of the structural changes, general HSQC-based triple resonance experiments could not be used for 62 kDa Hsp31 protein. Here, we prepared the per-deuterated Hsp31 and performed the TROSY-based triple resonance experiments for the bbCSs assignment. Here, detailed processes of per-deuteration and the NMR experiments are described for other similar NMR approaches.

• Ocean Science Journal
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• 제41권1호
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• pp.43-51
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• 2006

Concentration and distribution of Fe, Zn, Cu, Cd, Mn, Pb, Ni among subcellular fractions (cellular membrane structures and cytosol) and Zn, Cu, Cd among cytoplasmic proteins in the kidney and digestive gland of mussel Modiolus modiolus living along a polymetallic concentration gradient were studied. It was found in the kidney of M. modiolus from contaminated sites that the Fe percent increased in the "membrane" fraction, whereas Zn, Pb, Ni and Mn percent increased in the cytosol compared to the kidney of the control mussel. Note kidney cytosol of M. modiolus from clean and contaminated sites sequestered major parts of Cu and Cd. In the digestive gland of M. modiolus from contaminated sites Fe, Zn, Cd, Mn, Ni percent increased in the "membrane" fraction, whereas Cu, Pb percent increased in the cytosol compared to digestive gland of control mussel. Gel-filtration chromatography shows kidney of M. modiolus contains increased metallothionein-like protein levels irrespective of ambient dissolved metal concentrations. It was shown that the metal detoxification system in the kidney and digestive gland of M. modiolus was efficient under extremely high ambient metal levels. However, under complex environmental contamination in the kidney of M. modiolus, the metal detoxification capacity of metallothionein-like proteins was damaged.

• 미생물학회지
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• 제50권1호
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• pp.73-83
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• 2014

단백질이 풍부한 식품을 고온 하에서 조리하는 과정 중에 주로 발생되는 돌연변이원 heterocyclic amines (HCAs)에 대한 유산균의 결합력 및 제거능을 조사하였다. 당 발효능 및 16S rRNA 염기서열 분석을 통해 동정된 19종의 유산균 중 Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66 및 Lactobacillus plantarum D70의 세포이나 배양 상등액은 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1)과 3-amino-1-methyl-5Hpyrido[4,3-b] indole (Trp-P-2)에 의한 Salmonella typhimurium TA98 및 TA100의 돌연변이 유발을 억제할 수 있었다. HCAs에 대한 유산균 세포의 결합력은 cell wall, exopolysaccharide 및 peptidoglycan 보다 높게 나타났다. 한편, 이들의 결합력은 단백질 분해효소, 가열, sodium metaperiodate 및 산 처리에 의해 유의하게 감소되었으므로 세포벽에 존재하는 당이나 단백질 성분이 이들 HCAs을 결합시키는데 중요한 역할을 하는 것으로 확인되었다. 또한 E. faecium D12, L. acidophilus D38 및 E. faecalis D66의 결합력은 SDS나 금속이온에 의해 감소되었으므로 이들세포와 돌연변이원 사이에는 이온 결합이나 소수성 결합이 작용하는 것으로 추정되었다. 한편, HCAs 결합력이 높은 L. acidophilus D38과 L. plantarum D70은 장관 상피세포에 대한 부착력이 낮으므로 돌연변이원을 세포에 결합시켜 체외로 배출함으로써 독성물질을 제거하는데 효과적인 것으로 확인되었다.

• The Korean Journal of Ecology
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• 제24권1호
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• pp.35-43
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• 2001

카드뮴과 아연에 각각 그리고 동시에 노출한 총알고둥(Littorina brevicula)에서 중금속의 생체내 축적, 제거 및 세포내 분포 양상을 조사하였다. 총알고둥을 카드뮴 400 $\mu\textrm{g}$/L 또는 아연 3000 $\mu\textrm{g}$/L에 각각 90일간 노출하였을 경우, 각 중금속의 축적량은 노출기간에 따라 증가하였으며, 70일 이후에는 더 이상 축적량이 증가하지 않았다. 카드뮴과 아연을 동시에 노출하였을 경우에는 각각의 중금속에 노출하였을 경우에 비해 아연의 축적량은 증가하였으나, 카드뮴의 축적량은 감소하였다. 노출실험에 이어 수행한 42일간의 청장실험 결과, 카드뮴은 체외로 제거되지 않았으나, 아연은 제거되었다. 특히 카드뮴과 아연에 동시 노출한 총알고둥의 경우에 아연은 더 신속히 제거되었다. 총알고둥을 카드뮴과 아연에 각각 70일 동안 노출한 후, 체내로 흡수된 카드뮴의 약 60%가 soluble fraction에 분포하고 있었으며, 아연의 75%는 insoluble fraction에 분포하고 있었다. 이러한 경향은 카드뮴과 아연의 동시 노출시에도 유사하게 나타났다. 카드뮴과 아연은 soluble part내의 리간드(ligand) 와의 결합 양상에서도 차이를 나타냈는데, 카드뮴은 90% 이상이 약 6.5 kDa크기의 MBP-1(Metal-Binding Protein-1)과 결합하고 있었으나, 아연은 HMW(High molecular weight fraction, >60 kDa), MBP-1, MBP-2, LMW(Low molecular weight fraction <1 kDa)에 고루 분포하는 것으로 나타났다.

• The Korean Journal of Ecology
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• 제22권2호
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• pp.95-100
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• 1999

The heavy metal concentrations in seawater and winkles (Littorina brevicula) collected from the Onsan bay area in southeast of Korea were analyzed. The heavy metal concentrations in the seawater obtained from the most polluted site showed approximately 189. 205. and 110 fold higher cadmium, copper. and zinc concentrations, respectively. than the uncontaminated control site. The contamination levels of these metals in winkles were 11.08 - 2.35, 334.5 - 212.5, and 426.0 - 499.2$\mu\textrm{g}$ per gram dry body weight. respectively. The concentrations of all three metals in both the seawater and winkles decreased gradually with increasing distance from Daejeong stream, suggesting the stream being the major source of heavy metal input into the bay. Among the four body parts of digestive gland and gonad. gill. kidney, and remaining tissue in contaminated winkles, kidney showed the highest accumulation level of cadmium: copper and zinc, however. were more or less distributed among the four body parts. Upon gel filtration chromatography of the cytosol from the kidney of cadmium induced winkles, one cadmium peak corresponded to the elution peak of horse kidney metallothionein.

• Journal of Periodontal and Implant Science
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• 제38권sup2호
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• pp.343-354
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• 2008

Purpose: Aggregatibacter actinomycetemcomitans is associated with localized aggressive periodontitis. It produces cytolethal distending toxin (CDT), which induces cell cycle arrest in the G2/M phase. The CDT holotoxin is composed of CdtA, CdtB, and CdtC. CdtB has structural homology to human DNase I and is an active component of the CDT complex acting as a DNase. In particular, the pattern homology seen in the CdtB subunit has been associated with specific DNase I residues involved in enzyme catalysis, DNA binding, and metal ion binding. So, to study the functions and regulation of recombinant CdtB, we made up a quantity of functional recombinant CdtB and tested it in relation to the metal ion effect. Materials and Methods: We constructed the pET28a-cdtB plasmid from A. actinomycetemcomitans Y4 by genomic DNA PCR and expressed it in the BL21 (DE3) Escherichia coli system. We obtained the functional recombinant CdtB by the refolding system using the dialysis method and then analyzed the DNase activity and investigated the metal ion effect from plasmid digestion. Results: The recombinant CdtB subunit was expressed as the inclusion bodies. We were able to obtain functional recombinant CdtB subunit using refolding system. We confirmed that our refolded recombinant CdtB had DNase activity and was influenced by the metal ions $Mg^{2+}$ and $Ca^{2+}$. Conclusion: We suggest that the factors influencing recombinant CdtB may contribute to CDT associated diseases, such as periodontitis, endocarditic, meningitis, and osteomyelitis.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.233-239
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• 2021

Cyanobacteriochromes (CBCRs) are phytochrome-related photoreceptor proteins in cyanobacteria and cover a wide spectral range from ultraviolet to far-red. A single GAF domain that they contain can bind bilin(s) autocatalytically via heterologous recombination and then fluoresce, with potential applications as biomarkers and biosensors. Here, we report that a novel red/green CBCR GAF domain, SPI1085g2 from Spirulina subsalsa, covalently binds both phycocyanobilin (PCB) and phycoerythrobilin (PEB). The PCB-binding GAF domain exhibited canonical red/green photoconversion with weak fluorescence emission. However, the PEB-binding GAF domain, SPI1085g2-PEB, exhibited an intense orange fluorescence (λabs.max = 520 nm, λfluor.max = 555 nm), with a fluorescence quantum yield close to 1.0. The fluorescence of SPI1085g2-PEB was selectively and instantaneously quenched by copper ions in a concentration-dependent manner and exhibited reversibility upon treatment with the metal chelator EDTA. This study identified a novel PEB-binding cyanobacteriochrome-based fluorescent protein with the highest quantum yield reported to date and suggests its potential as a biosensor for the rapid detection of copper ions.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1159-1168
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• 2021

Ovotransferrin (OTF), an egg protein known as transferrin family protein, possess strong antimicrobial and antioxidant activity. This is because OTF has two iron binding sites, so it has a strong metal chelating ability. The present study aimed to evaluate the improved immune-enhancing activities of OTF hydrolysates produced using bromelain, pancreatin, and papain. The effects of OTF hydrolysates on the production and secretion of pro-inflammatory mediators in RAW 264.7 macrophages were confirmed. The production of nitric oxide (NO) was evaluated using Griess reagent and the expression of inducible nitric oxide synthase (iNOS) were evaluated using quantitative real-time polymerase chain reaction (PCR). And the production of pro-inflammatory cytokines (tumor necrosis factor [TNF]-α and interleukin [IL]-6) and the phagocytic activity of macrophages were evaluated using an ELISA assay and neutral red uptake assay, respectively. All OTF hydrolysates enhanced NO production by increasing iNOS mRNA expression. Treating RAW 264.7 macrophages with OTF hydrolysates increased the production of pro-inflammatory cytokines and the phagocytic activity. The production of NO and pro-inflammatory cytokines induced by OTF hydrolysates was inhibited by the addition of specific mitogen-activated protein kinase (MAPK) inhibitors. In conclusion, results indicated that all OTF hydrolysates activated RAW 264.7 macrophages by activating MAPK signaling pathway.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.10.2-10.2
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• 2011

The design and synthesis of protein-like polymers is a fundamental challenge in materials science. A biomimetic approach is to explore the impact of monomer sequence on non-natural polymer structure and function. We present the aqueous self-assembly of two peptoid polymers into extremely thin two-dimensional (2D) crystalline sheets directed by periodic amphiphilicity, electrostatic recognition and aromatic interactions. Peptoids are sequence-specific, oligo-N-substituted glycine polymers designed to mimic the structure and functionality of proteins. Mixing a 1:1 ratio of two oppositely charged peptoid 36 mers of a specific sequence in aqueous solution results in the formation of giant, free-floating sheets with only 2.7 nm thickness. Direct visualization of aligned individual peptoid chains in the sheet structure was achieved using aberration-corrected transmission electron microscopy. Specific binding of a protein to ligand-functionalized sheets was also demonstrated. The synthetic flexibility and biocompatibility of peptoids provide a flexible and robust platform for integrating functionality into defined 2D nanostructures. In the later part of my talk, we describe the use of metal ions to construct two-dimensional hybrid films that have the ability to self-heal. Incubation of biomimetic peptoid polymers with specific divalent metal ions results in the spontaneous formation of uniform multilayers at the air-water interface. We anticipate that ease of synthesis and transfer of these two-dimensional materials may have many potential applications in catalysis, gas storage and sensing, optics, nanomaterial synthesis, and environmentally responsive scaffolds.