• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.601-610
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• 2003

Biotin is a water-soluble vitamin used as a skin conditioning agent and promotes the formation of intercellular lipid layers through increased lipid synthesis, which improves the skin's natural barrier function. The anti-inflammatory effects of biotin have been investigated using in vitro assay models, such as MTT assay, measurements of concentrations of nitric oxide(NO), prostaglandin E2(PGE$_2$), and inhibition rate of 5-lipoxygenase(5-LOX). In comparison with biotin, other plant extracts were tested at the same time which were kudzu vine extract, sage extract, paeonia extract, and dipotassium glycyrrhetinate. Nitric oxide is a signal molecule with functions such as neurotransmission, local vascular relaxation, and anti-inflammation in many physiological and pathological processes. NO can cause apoptosis and necrosis of target cells such as keratinocytes and is generated from L-arginine by nitric oxide synthase (NOS). Prostanoids, including prostaglandins and thromboxanes, are generated by the phospholipase $A_2$/cyclooxygenase(COX) pathway, and leukotrienes are generated by the 5-lipoxygenase pathway from arachidonic acid. Prostaglandin E2 recently have been shown to be beneficial in the resolution of tissue injury and inflammation, also has been implicated as an immunosuppressive agent and plasma levels of PGE$_2$ are elevated in patients sustaining thermal injury. Lipoxygenase metabolites from arachidonic acid have been implicated in inflammation, anti-inflammatory activity of the raw materials was evaluated in vitro by the offered inhibition of lipoxygenase.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.435-440
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• 1990

Ten pigs infected with Aujeszky's disease virus (ADY) or hog cholera virus(HCV) were tested for the detection of virus antigens in frozens or paraffin-embedded sections by avidin-biotin-peroxidase complex(ABC) method. Tonsils, spleens, cerebra and buffy coats were examined for the immunohistochemical test. Where ADV antigen was detected by ABC, a dark brown deposit occurred in both the nucleus and the cytoplasm of lymphocytes and macrophages, however, HCV antigen was demonstrated in the cytoplasm of the infected cells. ADV-positive cells were most frequently detected in tonsils and cerebra, whereas, HCV -positive cells were frequently observed in spleens. And buffy coat were also good for both virus detection. The results suggested that ABC method is considered as an excellent and reliable tool for confirmative diagnosis of these viral diseases.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.306-311
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• 1993

The effects of methanol. used as a solvent for the hydrophobic substrate progesterone. on the morphology of Rhizopus nigricans and 11$\alpha$-hydroxylation of progesterone was investigated. The methanol tolerance of the 11$\alpha$-hydroxylase system in polyacrylamide immobilized R. nigricans mycelia as well as in free mycelia has been induced by adding various unsaturated fatty acids. biotin and ions into the cultivation medium. Immobilization of the cell seemed to protect the cells from denaturation by methanol. It gave higher reaction rate of progesterone than the free mycelia in the presence of methanol.500 $\mu$g/l of biotin was found to be the most effective induction agent for the methanol tolerance among tested chemicals. R. nixricans cells sustained its enzymatic activity at higher methanol concentrations as a result of accumulation of unsaturated fatty acids. especially oleic acid. in the membrane phospholipid.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.330-342
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• 2018

The Streptavidin and Biotin system has been studied most extensively as the high affinity non-covalent binding of Biotin to STR ($K_D=10^{-14}M$) and four Biotin binding sites in tetrameric Streptavidin makes this system useful for the production of multivalent antibody. For the application of this system, we cloned Streptavidin amplified from Streptomyces avidinii chromosome by PCR and fused to gene of hAY4 single-chain Fv antibody specific to death receptor 4 (DR4) which is a receptor for tumor necrosis factor ${\alpha}$ related apoptosis induced ligand. The hAY4 single-chain Fv antibody fused to Streptavidin expressed in Escherichia coli showed 43 kDa monomer in heated SDS-PAGE. However, this fusion protein shown in both non-heated SDS-PAGE and Size-exclusion chromatography exhibited 172 kDa as a tetramer suggesting that natural tetramerization of Streptavidin by non-covalent association induced hAY4 single-chain Fv tetramerization. This fusion protein retained a Biotin binding activity similar to natural Streptavidin as shown in Ouchterlony assay and ELISA. Death receptor 4 antigen binding activity of purified hAY4 single-chain Fv fused to Streptavidin was also confirmed by ELISA and Westernblot. In addition, surface plasmon resonance analysis showed 60-fold higher antigen binding affinity of the hAY4-STR than monomeric hAY4 ScFv due to tetramerization. In summary, hAY4 single-chain Fv fused to Streptavidin fusion protein was successfully expressed and purified as a soluble tetramer in E. coli and showed both Biotin and DR4 antigen binding activity suggesting possible production of bifunctional and tetrameric ScFv antibody.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.546-549
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• 2000

Liposomes and proteoliposomes, artificial membranes, can interact with many solutes, such as drugs, peptides and proteins. Immobilization of (proteo)liposomes as supramolecular aggregates on gold surfaces have potential applications in nanotechnology and biosensors. We demonstrate a quartz crystal analyzer (QCA) method to monitor the construction of multi layers of unilamellar liposomes based on avidin-biotin binding on gold surface using quartz crystal microbalance(QCM). Thus, QCA provides an on line and efficient method to detect the protein membranes construction and have applications to biosensing system.

• Journal of Sensor Science and Technology
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• v.4 no.4
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• pp.81-87
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• 1995

A novel biomaterial capable of incorporating biotinylated biomolecule has been synthesized. Our strategy is to biotinylate one-dimensional electroactive polymers and use a bridging streptavidin protein on Langmuir-Blodgett (LB) organized films. These copolymers are derivatized with long alkyl chains and biotin moieties to bind, respectively, to the hydrophobic surface and the biotinylated species, through the biotin and streptavidin complexation. We utilize the polymer assembly approach to attach a signal transducing biomolecule biotinylated phycoerythrin (B-PE) into this novel biomaterial by binding the unoccupied biotin binding sites on the bound streptavidin (4 sites total). The pressure-area isotherm of the protein injected monolayer showed area expansion. A characteristic fluorescent emission peak at 576nm was detected from the monolayer transferred onto a solid substrate. These observations demonstrated the promise of the organized thin polymer assemblies for their application to the sensor system.

• Korean Journal of Computational Design and Engineering
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• v.12 no.4
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• pp.298-307
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• 2007

In recent years, researchers are actively investigating new methods that are applicable for manufacturing micrometer to nanometer scale structures. Among them, optical tweezers that can manipulate microscopic objects using a laser is receiving one of the key attentions. Optical tweezers have been used actively in the field of science. For example, for measuring mechanical characteristics in the scale of piconewtons or for manipulating and sorting large numbers of particles, bacteria, cells. etc. However, little works have been reported for "manufacturing" objects. In this paper, we present a new method for manufacturing micrometer scale structures using micrometer scale biotin coated polystyrene particles. Particles will be controlled with a user interface that utilizes a CyberGlove and glued together by the bonding force between biotin and streptavidin.

• Bulletin of the Korean Chemical Society
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• v.17 no.11
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• pp.1018-1022
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• 1996

Adenosine deaminase (ADA) has been utilized as the label in devising a potentiometric homogeneous assay for riboflavin and riboflavin binding protein (RBP). The proposed homogeneous assay method employs an ADA-biotin conjugate as the signal generator and an avidin-riboflavin conjugate as the signal modulator in the solution phase. The catalytic activity of the ADA-biotin conjugate is inhibited in the presence of an excess amount of the avidin-riboflavin conjugate, and the observed inhibition is reversed in an amount proportional to the concentration of RBP added. When the analyte riboflavin is added to this mixture of ADA-biotin, avidin-riboflavin and RBP, the activity of the enzyme conjugate is re-inhibited in an amount proportional to the concentration of riboflavin. Since the enzyme label used in this system is ADA, an ammonia-producing enzyme, a potentiometric rather than photometric detection scheme is used to monitor the enzymatic activity in the assay.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.891-898
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• 2008

In this paper, we have studied on the possibilities of the biomaterial detection using single-walled carbon nanotube (SWNT) based on interdigital capacitors. For the four different configurations, such as interdigital capacitor, SWNT in the $5\;{\mu}m$ gap interdigital capacitor, biotinlated SWNT, and biotin and sreptavidin immobilization cases, the resonant frequency has been measured as 10.02 GHz, 11.02 GHz, 10.82 GHz, and 10.22 GHz, respectively. Assuming that the resonant frequency reflects the capacitance changes due to binding of two-different permittivity biomaterials, we have suggested an equivalent circuit model based on measured results, confirming the capacitance changes. For biotinlated SWNT and biotin-streptavidin immobilization cases, the capacitances are $C_b=0.55\;pF$ and $C_s=0.95\;pF$. In this work, we experimentally demonstrated that the specific biomaterial binding causes the capacitance change and therefore this gives rise to resonant frequency. In conclusion, we confirmed the sufficient possibility as CNT biosensor because an analyte biomaterial(streptavidin) binding arouses a considerable resonant frequency change.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.137-142
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• 2004

In this study, a simple procedure is described for patterning biotin on a glass substrate and then selectively immobilizing proteins of interest onto the biotin-patterned surface. Microcontact printing (CP) was used to generate the micropattern of biotin and to demonstrate the selective immobilization of proteins by using enhanced green fluorescent protein (EGFP) as a model protein, of which the C-terminus was fused to a core streptavidin (cSA) gene of Streptomyces avidinii. Confocal fluorescence microscopy was used to visualize the pattern of the immobilized protein (EGFP-cSA), and surface plasmon resonance was used to characterize biological activity of the immobilized EGFP-cSA. The results suggest that this strategy, which consists of a combination of $\mu$CP and cSA-fused proteins. is an effective way for fabricating biologically active substrates that are suitable for a wide variety of applications. one such being the use in protein-protein assays.