• Applied Biological Chemistry
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• v.49 no.3
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• pp.254-258
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• 2006

Vitellogenin has been known as a potent biomarker protein for the estrogenic activity in fish exposed to endocrine disruptors. In this study, a piezoelectric immunosensor making use of an anticarp vitellogenin antibody and an AT-cut quartz crystal microbalance as the biological component and transducer was prepared, followed by its application to the analysis of carp vitellogenin as follows. Antibody immobilization was conducted by chemisorption of a thiolated antibody with a heterobifunctional thiolation cross-linker, sulfosuccinimidyl 6-[3-(2-pyridyldithio)propionamido]hexanoate. The reaction buffer for the immunosensor system was optimized as 0.1 M sodium phosphate (pH 7.4). Concentration-dependent sensor responses were obtained in the vitellogenin concentrations ranging from 0.4864 to 486.4000 nM, with a linear correlation between vitellogenin concentration and frequency shift in double-logarithmic scale. The limit of detection of the immunosensor for carp vitellogenin was presumed as 0.4864 nM.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1896-1904
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• 2020

Muscle atrophy, characterized by a reduced number and size of myofibers, occurs due to immobilization, aging, and several chronic diseases. Leonurus japonicus, belonging to the Labiatae family, is widely used as a traditional medicine in Korea, China, and Japan. Previous studies have reported that L. japonicus has various physiological activities, such as anti-bacteria, anti-cancer, and liver protection. Leonurine, which is a major bioactive in L. japonicas, is known to possess biological effects including anti-inflammation, anti-fibrosis, anti-angiogenesis, and anti-diabetes. However, the preventive effects of L. japonicas and leonurine on muscle have not been reported. The current study aimed to determine the inhibitory effects of standardized L. japonicus extract (LJE) and leonurine on muscle atrophy by clarifying their underlying molecular mechanisms in tumor necrosis factor-alpha (TNF-α)-stimulated L6 myotubes. LJE and leonurine stimulated the phosphatidylinositol 3-kinase/Akt pathway that was reduced by TNF-α treatment. LJE and leonurine not only increased the mammalian target of rapamycin pathway for protein anabolism but also decreased the mRNA expression of E3 ubiquitin ligases by blocking the translocation of Forkhead box O, which is closely linked with proteolysis. Additionally, LJE and leonurine alleviated inflammatory responses by downregulating TNF-α and interleukin-6 mRNA expression and reducing the protein expression of nuclear factor-kappa B, a major transcriptional factor of proinflammatory cytokines. Collectively, LJE and leonurine have potential as therapeutic candidates for inhibiting the development of skeletal muscle atrophy by activating the PI3K/Akt pathway and reducing inflammatory responses.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.300-305
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• 2015

The glutamate decarboxylase gene (gadB) from Lactobacillus plantarum WCFS1 was cloned and expressed as an N-terminal hexa-histidine-tagged fusion protein in Escherichia coli BL21 (DE3) as the host strain. Purified glutamate decarboxylase (GAD) was immobilized onto porous silica beads by covalent coupling. The pH dependence of activity and stability of the immobilized GAD was significantly altered, when compared to those of the free enzyme. Immobilized GAD was stable in the range of pH 3.5 to 6.0. The resulting packed-bed reactor produced 41.7 g of γ-aminobutyric acid/l·h at 45℃.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.55-56
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• 2003

Silk fibroin (SF) is one of the typical protein polymer produced by silkworm, Bombyx mori. SF has been used as textile fiber and surgical suture fur thousands of years due to its unique gloss, handle, and mechanical properties. Recently, SF has been intensively studied to diverse usage for biotechlological and biomedical fields because of their reproducibility, environmental compatibility, non-toxicity, and biological compatibility. Based on its biocompatibility, the possible uses of regenerated SF have been proposed including substrate for cell culture[1], enzyme immobilization[2], and matrix for drug release[3]. (omitted)

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.2
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• pp.151-155
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• 2003

Using gel filtration chromatography, high molecular silk fibroin with high purity was obtained and silk flbroin microsphere particles (SFMP) could be simply made by spray dryer method. Also, some of the physicochemical properties of SFMP and morphology were investigated. The average molecular weight of pure silk fibroin protein dissolved in calcium chloride is about 61,500g/㏖ as measured by gel permeation chromatography. SFMP was spherical in shape, and particles, sized average of 2 ${\pm}$ 10 ${\mu}$, were observed by SEM and particle analyzer, respectively. Obtaining microspheres particles by spray dryer method accelerated the transition from the random coil to the $\beta$-sheet structure during spray dryer treatment. It was identified by the basic fourier transform infrared spectroscopy of SFMP. The swelling ratio of SFMP is majorly dependent on the pH of the solution, not on the occurred gelation. The characteristic structure, which might be applicable to immobilization of drugs is superior to other matrix materials for the use of biomaterials with skin affinity.

• BMB Reports
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• v.39 no.5
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• pp.636-641
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• 2006

Our previous studies indicated that native carbonic anhydrase does not interact with hydrophobic adsorbents and that it acquires this ability upon denaturation. In the present study, an apo form of the enzyme was prepared by removal of zinc and a comparative study was performed on some characteristic features of the apo and native forms by far- and near-UV circular dichroism (CD), intrinsic fluorescent spectroscopy, 1-anilino naphthalene-8-sulfonate (ANS) binding, fluorescence quenching by acrylamide, and Tm measurement. Results indicate that protein flexibility is enhanced and the hydrophobic sites become more exposed upon conversion to the apo form. Accordingly, the apo structure showed a greater affinity for interaction with hydrophobic adsorbents as compared with the native structure. As observed for the native enzyme, heat denaturation of the apo form promoted interaction with alkyl residues present on the adsorbents and, by cooling followed by addition of zinc, catalytically-active immobilized preparations were obtained.

• KSBB Journal
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• v.29 no.4
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• pp.239-243
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• 2014

Recently, there is a growing interest in efficient biomass pretreatment and saccharification processes to produce biofuels and biochemicals from renewable non-food biomass resources. In this study, glucose was produced from cellulose by immobilizing cellulase enzyme on chitosan beads which was reported to have high pH and temperature stability. The immobilized amounts of cellulase on chitosan beads linearly increased with increasing the concentrations of cellulase solution. The glucose production increased to 7.2 g/L from 1% carboxymethyl cellulose (CMC) substrate when immobilized at 20% cellulase solution. The maximum specific activity was 0.37 unit/mg protein when immobilized at 8% cellulase solution. At pH 7 and $37^{\circ}C$, the optimum reaction composition was 0.5 g beads/L from 1% CMC substrate. At this condition, the conversion to glucose completed at ca. 20 min.

• KSBB Journal
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• v.15 no.5
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• pp.497-500
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• 2000

Liposomes and proteoliposomes, artificial membranes, can interact with many solutes, such as drugs, peptides and proteins. The immobilization of (prot대)liposomes as supramolecular aggregates on gold surfaces have potential applications in nano and biosensor technology. We demonstrated a quartz crystal analyzer (QCA) based method to monitor the construction of multi-layers of unilamellar liposomes based on avidin-biotin binding on gold surfaces using a quartz crystal microbalance (QCM). Thus, the QCA provides an on line and efficient method of detecting the construction of protein membranes, which has applications in biosensing systems.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1647-1648
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• 2006

화학적, 생물학적 분석, 즉 특정 물질의 존재 유무를 측정하기 위해 마이크로캔틸레버라는 구조체를 제작하여 이를 바이오센서로 응용하였다. 마이크로캔틸레버의 장점은 분석하고자 하는 시료의 양이 적더라도 감지가 가능하고 이를 통하여 분석시간을 단축할 수 있다는 장점을 가지고 있다. 마이크로캔틸레버 구조물 제작을 위해 보편적으로 많이 이용되는 bulk 미세 가공 기술을 대신하여 표면 미세 가공기술을 이용하였다. 이러한 표면 미세 가공기술은 bulk 미세 가공기술에 비해 공정이 간단하고 값이 싸다는 장점이 있다. 또 액상 실험을 위하여 polydimethylsiloxane (PDMS)와 fused silica glass를 사용한 유체 제어 시스템을 제작하였다. 본 연구에서는 자기조림 이라는 특성을 이용하여 생물분자를 유체 제어 시스템 내의 마이크로캔틸레버 상단에 immobilization 시킨 후 마이크로캔틸레버 상, 하단의 표면 스트레스 차이에 따른 마이크로캔틸레버 자체의 휘어지는 정도를 측정하였다. 이러한 휘어지는 현상을 관찰함으로서 마이크로캔틸레버의 바이오센서로 응용 가능성을 확인한 수 있었다.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.175-180
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• 2009

This study was conducted to improve biological degradation efficiency of toluene as a model volatile organic compound (VOC) using yeast Candida tropicalis and to suggest an effective method for bioreactor operation. The yeast strain was immobilized with polyethylene glycol (PEG), alginate, and powdered activated carbon (PAC). The yeast-immobilized polymer media were used as fluidized materials in an airlift bioreactor. Polymer media without PAC were also made and operated in another airlift bioreactor. The two bioreactors showed toluene removal efficiencies ranging 80-96% at loading rates of $10-35 g/m^3-hr$, and the bioreactor containing the polymer media with PAC achieved higher removal efficiency. Protein contents in the liquid phase showed that the bioreactor using the yeast-immobilized polymer media with PAC had a higher rate of microbial growth initially than that without PAC. In addition, the microbial growth rate inside of the polymer media with PAC was five times higher than that without PAC. Consequently, the polymer media containing the yeast strain and PAC could enhance removal efficiencies for VOCs, and the immobilization method improve microbial activity and stability for a long-term operation of biological systems.