• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.775-775
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• 2005

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.196-200
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• 2004

• Journal of Life Science
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• v.13 no.1
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• pp.99-104
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• 2003

Aromatic compounds are of major concern among environmental pollutants due to their toxicity and persistence. To monitor aromatic compounds in a real time with a better sensitivity, a new method of SPR (surface plasmon resonance) based on DNA chip (Biacore 3000) was developed here. It is thought that CapR regulatory protein as a complex with phenol, could bind to their corresponding promoter, Po. Biotinylated DNA oligomers for the promoter was synthesized by PCR and coupled onto streptoavidin-linked CM5-chip. CapR regulatory proteins were purified after cloning their genes in pET21a (+) vector and expressing proteins. The interaction was assessed by the system where the regulatory proteins flowed with or without phenol through the cells of DNA chip. CapR regulatory protein even in the presence of phenol had no response to its promoter, Po, suggesting that other factor(s) might be required for the activation of Po promoter. The present work reveals a promising possibility of the SPR-based DNA chip in monitoring specific environmental pollutants in a real time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.147-154
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• 2009

This paper presents a grating~integrated SPR (Surface Plasmon Resonance) sensor chip for simple and inexpensive biomolecule detection. The grating-integrated SPR sensor chip has two sensing channels having a nano grating for SPR coupling. An external mirror is used for multi channel SPR sensing. The present sensor chip replaces bulky and expensive optical components, such as fiber-optic switches or special shaped prisms, resulting in a simple and inexpensive wavelength modulated multi-channel SPR sensing system. We fabricate a SPR sensor chip integrated with 835 nm-pitch gratings by a micromolding technique to reduce the fabrication cost. In the experimental characterization, the refractive index sensitivity of each sensing channel is measured as $321.8{\pm}8.1nm$/RI and $514.3{\pm}8.lnm$/RI, respectively. 0.5uM of the target biomolecule (streptavidin) was detected by a $1.13{\pm}0.16nm$ shift of the SPR dip in the 10%-biotinylated sample channel, while the SPR dip in the reference channel for environmental perturbation monitoring remained at the same position. From the experimental results, multi-channel biomolecule detection capability of the present grating-integrated SPR sensor chip has been verified. On the basis of the preliminary experiments, we successfully measured the binding reaction rate for the $2\;nM{\sim}200\;nM$ monoclonal-antibiotin, thus verifying biomolecule concentration detectability of the present SPR sensor chip. The binding reaction rates measured from the present SPR sensor chip agredd well with those from a commercialized SPR sensor.

• Korean Journal of Optics and Photonics
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• v.14 no.1
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• pp.97-102
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• 2003

Multi-channel images of 11-MUA(11-Mercaptoundecanoic acid) and 11-MUOH(11-Mercaptoundecanol) self-assembled monolayers were obtained by using two-dimensional surface plasmon resonance (SPR) absorption. The patterning process was simplified by exploiting direct photo-oxidation of thiol bonding (photolysis) instead of conventional photolithography. Sharper images were resolved by using a white light source in combination with a narrow bandpass filter in the visible region, minimizing the diffraction patterns on the images. The line profile calibration of the image contrast caused by different resonance conditions at each point on the sensor surface (at a fixed incident angle) enables us to discriminate the monolayer thickness in nanometer scale. Furthermore, there is no signal degradation such as photo bleaching or quenching, which are common in the detection methods based on fluorescence.

• Current Optics and Photonics
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• v.3 no.6
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• pp.541-547
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• 2019

A novel photonic crystal fiber (PCF) sensor with three D-shaped holes based on surface plasmon resonance (SPR) is analyzed in this paper. Three D-shaped holes are filled with the analyte, and the gold film is deposited on the side of three planes. The design of D-shaped holes with outward expansion can effectively solve the uniformity problem of metallized nano-coating, it is beneficial to the filling of the analyte and is convenient for real-time measurement of the analyte. Compared with the hexagonal lattice structure, the triangular arrangement of the clad air holes can significantly reduce the transmission loss of light and improve the sensitivity of the sensor. The influences of the air hole diameter, the distance between D-shaped holes and core, and the counterclockwise rotation angle of D-shaped holes on sensing performance are studied. The simulation results show that the wavelength sensitivity of the designed sensor can be as high as 10100 nm/RIU and the resolution can reach 9.9 × 10^-6 RIU.

• Korean Journal of Optics and Photonics
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• v.28 no.1
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• pp.28-32
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• 2017

In this research, we designed an LSPR sensor based on a thin-film multilayer comprising $TiO_2$ and $SiO_2$. The thickness of the overall substrate layer of the suggested multilayer LSPR sensor is limited to 100 nm, and the number of repeating $TiO_2$ and $SiO_2$ thin films is 1-4 within a limited thickness. Additionally, a nanowire structure with a gold thin film of 40 nm, height of 40 nm, period of 600 nm, and line width of 300 nm was formed on the multilayer. To design the variable wavelength-type SPR, the angle was fixed at $75^{\circ}$ and the wavelength was changed. We then simulated the system with the finite-element method (FEM) using Maxwell's equations. It was confirmed that the resonance wavelength became shorter as the number of multilayers increased when the refractive index was fixed. We found that the wavelength changes were more sensitive. However, no changes were observed when the number of the multilayers was three or higher.

• Animal Bioscience
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• v.34 no.4
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• pp.724-733
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• 2021

Objective: The objectives of this study were to investigate the direct antioxidative effect of 90 Kda heat shock protein (Hsp90) obtained from duck muscle. Methods: The interaction of Hsp90 with phospholipids and oxidized phospholipids was studied with surface plasmon resonance (SPR), and their further oxidation in the presence of Hsp90 was evaluated with thiobarbituric acid reactive substances (TBARS) assay. The scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS) was measured, and the electron paramagnetic resonance (EPR) spectroscopy in combination with 5-tert-Butoxycarbonyl-5-methyl-1-pyrroline-N-oxide and 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) was utilized to determine the abilities of Hsp90 in scavenging hydroxyl and PTIO radicals. Results: SPR showed Hsp90 could bind with both phospholipids and oxidized phospholipids, and prevent their further oxidation by the TBARS assay. The DPPH and ABTS scavenging activity increased with Hsp90 concentration, and could reach 27% and 20% respectively at the protein concentration of 50 μM. The EPR spectra demonstrated Hsp90 could directly scavenge ·OH and PTIO· radicals. Conclusion: This suggests that Hsp90, a natural antioxidant in meat, may play an important role in cellular defense against oxidative stress, and may have potential use in meat products.

• BMB Reports
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• v.40 no.5
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• pp.832-838
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• 2007

A novel inhibitory protein against blood coagulation factor Va (FVa) was purified from muscle protein of granulated ark (Tegillarca granosa, order Arcoida, marine bivalvia) by consecutive FPLC method using anion exchange and gel permeation chromatography. In the results of ESI-QTOF tandem mass analysis and database research, it was revealed that the purified T. granosa anticoagulant protein (TGAP) has 7.7 kDa of molecular mass and its partial sequence, HTHLQRAPHPNALGYHGK, has a high identity (64%) with serine/threonine kinase derived from Rhodopirellula baltica (order Planctomycetales, marine bacteria). TGAP could potently prolong thrombin time (TT), corresponding to inhibition of thrombin (FIIa) formation. Specific factor inhibitory assay showed that TGAP inhibits FVa among the major components of prothrombinase complex. In vitro assay for direct-binding affinity using surface plasmon resonance (SPR) spectrometer indicated that TGAP could be directly bound with FVa. In addition, the binding affinity of FVa to FII was decreased by addition of TGAP in dose-dependant manner ($IC_{50}$ value = 77.9 nM). These results illustrated that TGAP might interact with a heavy chain of FVa ($FVa_H$) bound to FII in prothrombin complex. The present study elucidated that non-cytotoxic T. granosa anticoagulant protein (TGAP) bound to FVa can prolong blood coagulation time by inhibiting conversion of FII to FIIa in blood coagulation cascade. In addition, TGAP did not significantly (P < 0.05) show fibrinolytic activity and cytotoxicity on venous endothelial cell line (ECV 304).

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.145-152
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• 2008

A cell-based in vitro exposure system was developed to determine whether oxidative stress plays a role in the cytotoxic effects of volatile organic compounds (VOCs) such as benzene, toluene, xylene, and chlorobenzene, using human epithelial HeLa cells. Thin films based on cysteine-terminated synthetic oligopeptides were fabricated for immobilization of the HeLa cells on a gold (Au) substrate. In addition, an immobilized cell-based sensor was applied to the electrochemical detection of the VOCs. Layer formation and immobilization of the cells were investigated with surface plasmon resonance (SPR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The adhered living cells were exposed to VOCs; this caused a change in the SPR angle and the VOC-specific electrochemical signal. In addition, VOC toxicity was found to correlate with the degree of nitric oxide (NO) generation and EIS. The primary reason for the marked increase in impedance was the change of aqueous electrolyte composition as a result of cell responses. The p53 and NF-${\kappa}B $ downregulation were closely related to the magnitude of growth inhibition associated with increasing concentrations of each VOC. Therefore, the proposed cell immobilization method, using a self-assembly technique and VOC-specific electrochemical signals, can be applied to construct a cell microarray for onsite VOC monitoring.