• Mycobiology
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• v.41 no.3
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• pp.149-154
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• 2013

An ${\alpha}$-glucosidase inhibitor was developed from Aspergillus oryzae N159-1, which was screened from traditional fermented Korean foods. The intracellular concentration of the inhibitor reached its highest level when the fungus was cultured in tryptic soy broth medium at $27^{\circ}C$ for five days. The inhibitor was purified using a series of purification steps involving ultrafiltration, Sephadex G-25 gel permeation chromatography, strong cation exchange solid phase extraction, reverse-phase high performance liquid chromatography, and size exclusion chromatography. The final yield of the purification was 1.9%. Results of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis indicated that the purified ${\alpha}$-glucosidase inhibitor was a tri-peptide, Pro-Phe-Pro, with the molecular weight of 360.1 Da. The IC50 value of the peptide against ${\alpha}$-glucosidase activity was 3.1 mg/mL. Using Lineweaver-Burk plot analysis, the inhibition pattern indicated that the inhibitor acts as a mixed type inhibitor.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.119-125
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• 1990

A Potent inhibitor of trypsin and other various serine proteases including chymotrypsin, elastase, kallikrein, plasmin and subtilisin, has been purified to homogeneity from chick skeletal muscle by convendonal chromatographic procedures. The Inhibitor has an apparent molecular weight of 66, 000 dalton as determined by gel filtration. When the purified inhibitor was electrophoresed in the presence of sodium dodecyl sulfate, there appeared rwo protein bands having molecular weights of 66, 000 and 64, 000 dalton. The 64, 000 dalton protein seems to be the product of 66, 000 dalton protein by a lin'ited proteolysis during the purification procedure or in viuo. Thus, it seems to consist of a single polypeptide. The inhibitor appeared to be glycoprotein and have an isoelectric point of 7.4. It contains relatively large amount (8.33 mole%) of cysteine residues.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.524-530
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• 2006

Two protease inhibitors of 67 and 18 kDa, respectively, were purified from the eggs of glass fish, Liparis tanakai, by affinity chromatography and electro-elution method. The high molecular weight (HMW) protein was purified with a specific inhibitory activity, yield, and purity of 18.46 U/mg, 0.07%, and 131.86 fold, respectively, and was further characterized: Optimal temperature and pH for inhibitory activity of the HMW glassfish egg protease inhibitor were $40^{\circ}C$ and pH 6, respectively, and it was stable between $5^{\circ}C\;and\;50^{\circ}C$ in the pH range of 5-6 with maximal stability at pH 6. It was shown to be a competitive inhibitor against papain with an inhibition constant $(K_i)$ of 97.02 nM. Moreover, the 67 kDa protein inhibited cathepsin, a cysteine protease, more effectively than did an egg-white protease inhibitor. The HMW glassfish egg protease inhibitor was classified as a member of the family III (kininogen).

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.213-217
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• 1995

The effect of inorganic phosphate on the fermentative production of aminopeptidase M inhibitors MR-387A and B by Streptomyces sp. SL-387 has been studied. With inorganic phosphate concentrations higher than 0.78 mM, an inverse correlation was found between the maximum inhibitor production and the initial phosphate concentration added. Growth sensitivity of this actinomycete to arsenate, a phosphate analogue, and the use of magnesium carbonate, a phosphate-trapping agent, suggested that the inhibitor formation was under phosphate repression. Exogenous ATP further increased the degree of phosphate interference in both phosphate-repressed and non repressed culture conditions. The use of a phosphate analogue and a protein synthesis inhibitor also suggested that the phosphate itself repressed inhibitor formation.

• YAKHAK HOEJI
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• v.36 no.4
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• pp.390-396
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• 1992

Streptomyces minoensis DMCJ-144 isolated from soil produces the ${\alpha}-amylase$ inhibitor. Optimum culture conditions for ${\alpha}-amylase$ inhibitor production of the strain were determined in this experiment. The optimum composition of the culture medium was studied by supplementing various carbon sources, nitrogen sources, vitamins, and metal salts to the basal medium containing 1% glucose, 0.1% asparagine, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $K_2HPO_4$, 0.005% NaCl. Other culture conditions such as the culture temperature, initial pH of the medium, aeration, and culture time were also investigated. When the strain was cultured in a 100 ml flask containing 20 ml of 2% glucose, 0.5% beef extract, 0.0002% riboflavin, 0.0002% thiamine HCI, 0.01% $ZnCl_2$, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $CuSO_4{\cdot}5H_2O$, 0.005% NaCl, pH 7.2, 180 rpm at $30^{\circ}C$, the maximum production of the ${\alpha}-amylase$ inhibitor was observed after 5 days of the cultivation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.33-34
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• 2023

Corrosion of reinforcement steel is a major cause of deterioration in reinforced concrete (RC) structures. In order to protect these structures from corrosion, corrosion inhibitors are added to the concrete mix. In recent years, zwitterionic compounds have shown promising results as corrosion inhibitors in concrete due to their ability to form a protective layer on the surface of the reinforcement steel. The experimental study involves preparing concrete samples with different concentrations of adding the hybrid corrosion inhibitor at a high concentration of chloride ions. This study aims to determine the chloride threshold value and service life of hybrid corrosion inhibitors in reinforced concrete based on zwitterions. The samples are subjected to accelerated corrosion tests in a chloride environment to determine the threshold value and service life of the corrosion inhibitor. The effect of hybrid inhibitor on mechanical properties is guaranteed in allowable range. The chloride threshold concentration and service life of hybrid inhibitor containing samples perform greater than those of plain RC.

• Korean Journal of Plant Resources
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• v.31 no.3
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• pp.218-227
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• 2018

In this study, we investigated the effect of the extracts from Vaccinium oldhamii on cell proliferation and the regulatory mechanisms of cyclin D1 protein level in human cancer cells. The branch extracts from Vaccinium oldhamii (VOB) showed higher inhibitor effect against the cell growth than leave extracts (VOL) and fruit extracts (VOF) in human colorectal cancer, breast cancer, prostate cancer, non-small lung cancer, pancreatic cancer and liver cancer cells. In addition, VOB decreased cyclin D1 level at both protein and mRNA level. MG132 treatment attenuated VOB-mediated cyclin D1 downregulation. A point mutation of threonine-286 to alanine attenuated cyclin D1 degradation by VOB. In addition, the inhibition of nuclear export by leptomycin B (LMB) attenuated cyclin D1 degradation by VOB. But, the treatment of PD98059 (ERK1/2 inhibitor), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor), LiCl ($GSK3{\beta}$ inhibitor), LY294002 (PI3K inhibitor) or BAY 11-7082 ($I{\kappa}K$ inhibitor) did not affect VOB-induced cyclin D1 degradation. In conclusion, VOB induced cyclin D1 degradation through redistribution of cyclin D1 from the nucleus to cytoplasm via T286 phosphorylation of cyclin D1, which resulted in the inhibition of cancer cell proliferation.

• Biomedical Science Letters
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• v.22 no.2
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• pp.60-64
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• 2016

In the pathogenesis of inflammatory diseases such as allergies, S100A8 acts as an important molecule and T lymphocytes are essential cytokine-releasing cells. In this study, we investigated the effect of S100A8 on release of cytokines, specifically MCP-1, IL-6, and IL-8 in T cells, and its associated signaling mechanism. S100A8 increased secretion of MCP-1, IL-6, and IL-8 in a time- and dose-dependent manner. Elevated secretion of MCP-1, IL-6, and IL-8 due to S100A8 was inhibited by the TLR4 inhibitor TLR4i, the PI3K inhibitor LY294002, the $PKC{\delta}$ inhibitor rottlerin, the ERK inhibitor PD98059, the p38 MAPK inhibitor SB202190, the JNK inhibitor SP600125, and the NF-${\kappa}B$ inhibitor BAY-11-7085. S100A8 induced phosphorylation of ERK, p38 MAPK, and JNK in a time-dependent manner, and activation was suppressed by TLR4i, LY294002, and rottlerin. S100A8 induced NF-${\kappa}B$ activation by $I{\kappa}-B{\alpha}$ degradation, and NF-${\kappa}B$ activity was suppressed by PD98059, SB202190, and SP600125. These results indicate that S100A8 induces cytokine release via TLR4. Study of PI3K, $PKC{\delta}$, MAPKs, and NF-${\kappa}B$ will contribute to elucidation of the S100A8-invovled mechanism.

• Tuberculosis and Respiratory Diseases
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• v.70 no.6
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• pp.462-473
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• 2011

Background: Smoking is a risk factor for idiopathic pulmonary fibrosis (IPF), but the mechanism of the association remains obscure. There is evidence demonstrating that plasminogen activator inhibitor-1 (PAI-1) is involved in the progression of pulmonary fibrosis. This study was to determine whether the administration of small interfering RNA (siRNA) targeting PAI-1 or PAI-1 inhibitor to the cigarette smoking extract (CSE)-exposed rat alveolar type II epithelial cells (ATII cells) limits the epithelial-mesenchymal transition (EMT). Methods: ATII cells were isolated from lung of SD-rat using percoll gradient method and cultured with 5% CSE. The EMT was determined from the ATII cells by measuring the real-time RT PCR and western blotting after the PAI-1 siRNA transfection to the cells and after administration of tiplaxtinin, an inhibitor of PAI-1. The effect of PAI-1 inhibitor was also evaluated in the bleomycin-induced rats. Results: PAI-1 was overexpressed in the smoking exposed ATII cells and was directly associated with EMT. The EMT from the ATII cells was suppressed by PAI-1 siRNA transfection or administration of tiplaxtinin. Signaling pathways for EMT by smoking extract were through the phosphorylation of SMAD2 and ERK1/2, and finally Snail expression. Tiplaxtinin also suppressed the pulmonary fibrosis and PAI-1 expression in the bleomycin-induced rats. Conclusion: Our data shows that CSE induces rat ATII cells to undergo EMT by PAI-1 via SMAD2-ERK1/2-Snail activation. This suppression of EMT by PAI-1 siRNA transfection or PAI-1 inhibitor in primary type II alveolar epithelial cells might be involved in the attenuation of bleomycin-induced pulmonary fibrosis in rats.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.2
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• pp.171-175
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• 1990

One thousand and seven hundreds and six soybean land reces and 103 wild soybeans of Korea, and 167 cultivars and 71 wild soybeans of exotic were analyzed using polyacrylamide gel electrophoresis to study the distribution of trypsin inhibitor phenotypes. The four ti/ti lines were observed only in Korean native land races. The Ti$\^$*/a allele of cultivar was found to be the highest in Chinese soybean (0,9888) than in Korean soybean(0.8347) and Japanese soybean (0.5954). The heterozygosity of typsin inhibitor in Korean lines occured in relatively high ratio, The percentages of heterozygosity of the Korean land race and wild soybean are 3.6% (N=61) and 9.7%(N=10), respectively.