• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1112-1118
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• 1999

Galectin-3 plays an important role in cell development, differentiation and cancer metastasis, including cell-cell/extracellular matrix (ECM) interactions and is supposed to have an effect of apoptosis on T-cells in thymic clonal selection. In this study, to know the effect of galectin-3 on thymocyte development, we used recombinant human galectin-3 (rHgal-3) from Escherichia coli, JM105, which was inserted with human gal-3 gene-transformed plasmid vector (prGal-3) to express human galectin-3. Expressed rHgal-3 was confirmed by western blot using the culture supernant of hybridoma (M3/38) producing monoclonal antibody to human galectin-3. Sepharose gel affinity chromatography was used to purify the expressed rHgal-3. Thymocytes and hepatocytes from 6-week-old male BALB/c mice were incubated with rHgal-3 and showed marked increase of apoptotic population on analysis using flow cytometry with 7-AAD in a dosedependent manner. However, rHgal-3 failed to induce apoptosis on hepatocytes. Interestingly, this apoptotic effect was not inhibited by lactose, a specific lectin domain inhibitor. From these results, we concluded that extrinsic -3 induces apoptosis on mouse thymocytes, and galectin-3 may have an apoptotic effect on T-cells in thymic clonal selection.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.110-114
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• 1999

The present study was conducted to investigate the preparative methods of agarose for gel electrophoresis from agar. Naturally occuring agar consists of two main polysaccharides, the neutral polysaccharide agarose and the acid sulphated polysaccharide agaropectin. The sulphate and carboxyl functions of the agar are accumulated in the agaropectin. The hydrophilic, non-ionogenic, rigid and transparent gel matrix of the agarose was found to be suitable for gel electrophoresis gel filtration and affinity chromatography. Agar was purified by chitosan treatment, cetylpyridinium chloride (CPC) treatment, and polyethylene glycol (PEG) treatment. Yields of agarose purified from agar with chitosan, CPC and PEG were 56.7%, 55.6% and 62.3%. It was proper to treat with chitosan in preparative methods of agarose for gel electrophoresis from agar.

• Journal of the Korean Applied Science and Technology
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• v.25 no.1
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• pp.15-22
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• 2008

The effects of fillers on the mechanical and thermal properties of glass/novolac composites have been studied. The matrix polymer and reinforcement were novolac type phenolic resin and milled glass fiber, respectively. Three different fillers, such as calcium carbonate, aluminum oxide, and wood powder were used for glass fiber reinforced plastic(GFRP) manufacture. Gravity, moisture content, tensile and flexural strength were measured to analyze the mechanical properties of GFRP and the final composites was burned in the electronic furnace at $1000^{\circ}C$ to confirm thermal properties GFRP containing aluminium oxide shows the highest thermal stability with 32% of weight loss at $1000^{\circ}C$ for one hour. GFRP containing calcium carbonate shows the maximum flexural strength (146 MPa), but that containing wood powder dose the highest tensile strength (65 MPa). Conclusively, we found that the characteristics of final composites strongly depend on several factors, such as types of materials, contents and chemical affinity of fillers. Therefore, it is very important to set up the combination of fillers for GFRP manufacturing to improve both mechanical and thermal properties at the same time.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.9 no.1
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• pp.49-55
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• 2023

Tumors are encircled by various non-cancerous cell types in the extracellular matrix, including fibroblasts, endothelial cells, immune cells, and cytokines. Fibroblasts are the most critical cells in the tumor stroma and play an important role in tumor development, which has been highlighted in some epithelial cancers. Many studies have shown a tight connection between cancerous cells and fibroblasts in the last decade. Regulatory factors secreted into the tumor environment by special fibroblast cells, cancer-associated fibroblasts (CAFs), play an important role in tumor and vessel development, metastasis, and therapy resistance. This review addresses the development of FAP inhibitors, emphasizing the first, second, and latest generations. First-generation inhibitors exhibit low selectivity and chemical stability, encouraging researchers to develop new scaffolds based on preclinical and clinical data. Second-generation enzymes such as UAMC-1110 demonstrated enhanced FAP binding and better selectivity. Targeted treatment and diagnostic imaging have become possible by further developing radionuclide-labeled fibroblast activation protein inhibitors (FAPIs). Although all three FAPIs (01, 02, and 04) showed excellent preclinical and clinical findings. The final optimization of these FAPI scaffolds resulted in FAPI-46 with the highest tumor-to-background ratio and better binding affinity.

• Membrane Journal
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• v.28 no.1
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• pp.55-61
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• 2018

With vigorous development of petroleum and chemical industry, emission of carbon dioxide has attracted tremendous attention globally due to global warming problem and abnormal climate change. To address these problems, in this study, a PEGBEM-g-POEM graft copolymer with high $CO_2$ affinity was synthesized and $CaCO_3$ was incorporated to form mixed matrix membranes (MMMs) for enhancement of $CO_2$ permeance. By varying the addition weight of $CaCO_3$ in MMMs, high separation performance of $CO_2$ over $N_2$ was obtained. At 50 wt% loading of $CaCO_3$, the greatest separation performance was obtained with an enhanced $CO_2$ permeance from 22.5 to 28.16 GPU and slightly increased $CO_2/N_2$ selectivity from 44.7 to 45.42. It resulted from the increased $CO_2$ solubility of MMMs due to specific interaction between $CaCO_3$ and $CO_2$ molecules. Upon excess loading of $CaCO_3$, MMMs exhibited loss of $CO_2$ separation performance due to the formation of interfacial defects. Based on this result, it is considered that the proper addition of $CaCO_3$ is crucial for improvement of $CO_2$ separation performance.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.95-95
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• 1997

Among the various receptor molecules discovered so far the ${\beta}$2-adrenergic receptors have been regarded as excellent model systems for the so called 7 transmembrane helix receptor and have been the focus of extensive studies. For the analysis of receptor structure and function a monoclonal antibody plays a crucial role, thus providing useful tools for the study of receptor. However, because of the minute quantity of receptor molecules which could be obtained from natural sources, the generation of specific monoclonal antibody against receptor molecules from the purified receptors has been regarded as virtually impractical in consideration of cost and experimental times. The purpose of the present study was to generate and characterize a monoclonal antibody against human ${\beta}$2-adrenergic receptor. For the production of antibody, C-terminal regions of the human ${\beta}$2-adrenergic receptor was produced as a fusion protein with Glutathion S-transferase (GST) in E. Coli. The expression of the fusion protein was identified by SDS-PAGE and Western blot using monoclonal anti-GST antibody. The fusion protein was purified to an apparent homogeniety by affinity chromatography with Glutathion Sepharose CL-4B and used as an antigen for the immunization of BALB/C mice. The Production of monoclonal antibody was achieved by fusion of the immunized spleen cells and SP/2-0 myeloma cells. Positive hybridomas were screened by ELISA and were cloned by two consecutive rounds of limiting dilution. The monoclonal antibody produced in this study (mAb${\beta}$C02) was IgM type and purified by immunoaffinity chromatography using anti-mouse IgM agarose as an affinity matrix. MAb${\beta}$C02 showed strong and specific immunoreactivity against both the fusion protein and human ${\beta}$2-adrenergic receptor in ELISA and Western blot. The molecular weight of immunoreactive band was 64 kDa and exactly coincided with the previously reported molecular weight of ${\beta}$2-adrenergic recepters. The results of the present study suggest that mAb${\beta}$C02 may be used for the study of receptor function and regulation in normal or nonphysiological status.

• Archives of Plastic Surgery
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• v.33 no.1
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• pp.46-52
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• 2006

High-density micromass culture was needed to take three dimensions culture with ASCs(adipose derived stromal cells) and chondrogenesis. However, the synthetic polymer has hydrophobic character and low affinity to cells and other biomolecules. Therefore, the surface modification without changes of physical and chemical properties is necessary for more suitable condition to cells and biomolecules. This study was performed to investigate the effect of surface modification of poly (lactic-co-glycolic acid)(PLGA) scaffold by plasma treatment (P(+)) on the adhesion, proliferation and chondrogenesis of ASCs, and not plasma treatment (P(-)). ASCs were isolated from human subcutaneous adipose tissue obtained by lipectomy and liposuction. At 1 hour 30 minutes and 3days after cell seeding onto the P(-) group and the P(+) group, total DNA amount of attached and proliferated ASCs markedly increased in the P(+) group (p < 0.05). The changes of the actin under confocal microscope were done for evaluation of cellular affinity, at 1 hour 30 minutes, the shape of the cells was spherical form in all group. At 3rd day, the shape of the cells was fiber network form and finely arranged in P(+) group rather than in P(-) group. RT-PCR analysis of cartilage-specific type II collagen and link protein were expressed in 1, 2 weeks of induction. Amount of Glycoaminoglycan (GAG) markedly increased in P(+) group(p < 0.05). In a week, extracellular matrix was not observed in the Alcian blue and Safranin O staining. However in 2 weeks, it was observed that sulfated proteoglycan increased in P(+) group rather than in P(-) group. In conclusion, we recognized that plasma treatment of PLGA scaffold could increase the hydrophilic property of cells, and provide suitable environment for high-density micromass culture to chondrogenesis

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2419-2424
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• 2013

Guanosine-5'-diphosphate 3'-diphosphate (ppGpp) serves as alarmone in bacterial stringent responses. In this study, an affinity column was constructed by immobilizing ppGpp to NHS-Sepharose for isolating ppGpp-binding proteins. A novel ppGpp-binding protein, YjgA, was isolated and characterized by MALDI-TOF MS (matrix-assisted laser desorption ionization-time-of-flight mass spectrometry) coupled with two-dimensional gel electrophoresis. YjgA and truncated forms of YjgA were cloned and over-expressed in BL21 (DE3). The binding affinity of YjgA to ppGpp was determined by equilibrium dialysis. The interaction of YjgA with ppGpp was very specific, considering that the dissociation constant of YjgA with ppGpp was measured as $5.2{\pm}2.0{\mu}M$, while the affinities to GTP and GDP were about 60 and 30 times weaker than ppGpp. Expression of yjgA gene in Escherichia coli K-12 MG1655 was examined by reverse transcription polymerase chain reaction (RT-PCR). RT-PCR results revealed that yjgA was expressed from early to late stationary phase. The yjgA deletion mutant exhibited decreased cell number at stationary phase compared to parent strain and the over-expression of YjgA increased the cell number. These results suggested that YjgA might stimulate cell division under stationary phase. In most prokaryotic genome, about half of the protein candidates are hypothetical, that are expected to be expressed but there is no experimental report on their functions. The approach utilized in this study may serve as an effective mean to probe the functions of hypothetical proteins.

• Polymer(Korea)
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• v.39 no.1
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• pp.136-143
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• 2015

Poly(vinyl alcohol) (PVA) was grafted onto the multiwalled carbon nanotube (MWCNT) using ultrasound in water and modified MWCNT/PVA nanocomposite was prepared. Modified MWCNT had a good affinity with PVA matrix and showed improved dispersion state along with uniform properties. Therefore, the electrical percolation threshold was observed at 0.1 wt% MWCNT. 3.0 wt% modified MWCNT/PVA composite had 50% higher tensile strength, 430% higher elongation at break, and 100% greater modulus. Since the modified MWCNT acted as a nucleation agent, the crystallization temperature increased to $8.5^{\circ}C$ and the crystallinity increased to 11.5% at 5.0 wt% loading concentration.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2787-2790
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• 2014

Quercetin is a major dietary flavonoid found in onions, apples, tea, and red wine, and potentially has beneficial effects on disease prevention. We carried out this study to investigate the effect of quercetin on UVB-induced matrix metalloproteinase-1 (MMP-1) expression in human keratinocyte HaCaT cells and to further understand the mechanisms of its action. The anti-inflammatory activity of quercetin was investigated and quercetin significantly suppressed the NO production in LPS-stimulated RAW264.7 mouse macrophages. Post treatment of quercetin decreased UV irradiation-induced phosphorylation of JNK, p38 MAPK, and ERK by 91%, 21%, and 17%, respectively. MMP-1 is mainly responsible for the degradation of dermal collagen during the aging process of human skin and quercetin suppressed the UVB-induced MMP-1 by 94%. Binding studies revealed that quercetin binds to p38 with high binding affinity ($1.85{\times}10^6M^{-1}$). The binding model showed that the 4'-hydroxy groups of the B-ring of quercetin participated in hydrogen bonding interactions with the side chains of Lys53, Glu71, and Asp168 and the 5-hydroxy group of the A-ring formed a hydrogen bond with the backbone amide of Met109. The major finding of this study shows that quercetin inhibits phosphorylation of JNK, p38 MAPK, and ERK pathway leading to the prevention of MMP-1 expression in human keratinocyte HaCaT cells. Therefore, our findings suggested the potentials of quercetin as a skin anti-photoaging agent.