• 한국미생물·생명공학회지
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• 제49권4호
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• pp.510-518
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• 2021

Bacteriophages are considered excellent sensing elements for platforms detecting bacteria. However, their lytic cycle has restricted their efficacy. Here, we used the minor coat protein pIII domain (N1N2) of phage CTXφ to construct a novel surface plasmon resonance (SPR) biosensor that could detect Vibrio cholerae. N1N2 harboring the domains required for phage adsorption and entry was obtained from Escherichia coli using recombinant protein expression and purification. SDS-PAGE revealed an approximate size of 30 kDa for N1N2. Dot blot and transmission electron microscopy analyses revealed that the protein bound to the host V. cholerae but not to non-host E. coli K-12 cells. Next, we used amine-coupling to develop a novel recombinant N1N2 (rN1N2)-functionalized SPR biosensor by immobilizing rN1N2 proteins on gold substrates and using SPR to monitor the binding kinetics of the proteins with target bacteria. We observed rapid detection of V. cholerae in the range of approximately 10³ to 10⁹ CFU/ml but not of E. coli at any tested concentration, thereby confirming that the biosensor exhibited differential recognition and binding. The results indicate that the novel biosensor can rapidly monitor a target pathogenic microorganism in the environment and is very useful for monitoring food safety and facilitating early disease prevention.

• 한국산업보건학회지
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• 제29권1호
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• pp.42-49
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• 2019

Objective: Chronic obstructive pulmonary disease(COPD) is characterized by persistent airflow limitations associated with chronic inflammatory response due to noxious particles or gases in the lung. Iron deficiency is associated with chronic inflammation, such as COPD. The aim of this study was to evaluate the relationship among iron deficiency, iron homeostasis, and inflammation in retired miners with COPD. Methods: The serum levels of ferritin, soluble transferrin receptor(sTfR), and transferrin saturation(TSat) as biomarkers for iron deficiency and high-sensitivity C-reactive protein(hsCRP) as a biomarker for inflammation and hepcidin as a biomarker for iron homeostasis were measured in 93 male subjects. Iron deficiency was defined as any one or more of (1) sTfR>28.1 nmol/L, (2) TSat<16%, and (3) ferritin< $12{\mu}g/L$. Results: Iron deficiency was found 28% of the study subjects. Median levels of serum hsCRP was significantly increased related to airflow limitation of COPD(GOLD 1, $0.09{\mu}g/dL$ vs. GOLD 2, $0.17{\mu}g/dL$ vs. GOLD $3{\leq}$, $0.30{\mu}g/dL$, p=0.010), and was positively correlated with hepcidin(p=0.009). Mean level of serum hepcidin was lower in COPD subjects with iron deficiency(p=0.004) and serum levels of hepcidin was negatively correlated with %$FEV_1$ predicted(p=0.030). Conclusions: These results suggest that high serum levels of hepcidin are related to severe airflow limitation or inflammation and can decrease iron availability, regardless of iron status.

• 한국산업보건학회지
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• 제29권2호
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• pp.251-258
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• 2019

Objective: Chronic obstructive pulmonary disease(COPD) is characterized by persistent airflow limitations associated with chronic inflammatory response due to noxious particles or gases in the lung. Inflammation and oxidative stress are associated with COPD. The aim of this study was to evaluate the relationship among inflammation, oxidative stress, and airflow limitation severity in retired miners with COPD. Methods: The levels of serum high-sensitivity C-reactive protein(hsCRP) as a biomarker for inflammation, degree of reactive oxygen metabolites(dROMs) and biological antioxidants potential(BAP) in plasma as biomarkers for oxidative stress were measured in 211 male subjects with COPD. Degree of airflow limitation severity as determined by spirometry was divided into three grades grouped according to the classification of the Global Initiatives for Obstructive Lung Disease(GOLD)(1, mild; 2, moderate; $3{\leq}$, severe or more) using a fixed ratio, post- bronchodilator $FEV_1/FVC$ < 0.7. Results: Mean levels of dROMs significantly increased in relation to airflow limitation severity(GOLD 1, 317.8 U.CARR vs. GOLD 2, 320.3 U.CARR vs. GOLD $3{\leq}$, 350.9 U.CARR, p=0.047) and dROMs levels were correlated with serum hsCRP levels(r=0.514, p<0.001). Mean levels of hsCRP were higher in current smokers(non-smoker, 1.47 mg/L vs. smoker, 2.34 mg/L, p=0.006), and tended to increase with degree of airflow limitation severity(p=0.071). Mean levels of BAP were lower in current smokers(non-smoker, $1873{\mu}mol/L$ vs. smoker, $1754{\mu}mol/L$, p=0.006). Conclusions: These results suggest that inflammation and oxidative stress are related to airflow limitation severity in retired miners with COPD, and there was a correlation between inflammation and oxidative stress.

• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.200-206
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• 2007

Pharmacophore models for lymphocyte-specific protein tyrosine kinase (P56 LCK) were developed using CATALYST HypoGen with a training set comprising of 25 different P56 LCK inhibitors. The best quantitative pharmacophore hypothesis comprises of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic aliphatic and one ring aromatic features with correlation coefficient of 0.941, root mean square deviation (RMSD) of 0.933 and cost difference (null cost-total cost) of 66.23. The pharmacophore model was validated by two methods and the validated model was further used to search databases for new compounds with good estimated LCK inhibitory activity. These compounds were evaluated for their binding properties at the active site by molecular docking studies using GOLD software. The compounds with good estimated activity and docking scores were evaluated for physiological properties based on Lipinski's rules. Finally 68 compounds satisfied all the properties required to be a successful inhibitor candidate.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1291-1299
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• 2014

Recently, multifunctional nanomaterials have been developed as nanotherapeutic agents for cellular imaging and targeted cancer treatment because of their ease of synthesis and low cytotoxicity. In this study, we developed a multifunctional, two-component nanorod consisting of gold (Au) and nickel (Ni) blocks that enables dual-fluorescence imaging and the targeted delivery of small interfering RNA (siRNA) to improve cancer treatment. Fluorescein isothiocyanate-labeled luteinizing hormone-releasing hormone (LHRH) peptides were attached to the surface of a Ni block via a histidine-tagged LHRH interaction to specifically bind to a breast cancer cell line, MCF-7. The Au block was modified with TAMRA-labeled thiolated siRNA in order to knock down the vascular endothelial growth factor protein to inhibit cancer growth. These two-component nanorods actively targeted and internalized into MCF-7 cells to induce apoptosis through RNA interference. This study demonstrates the feasibility of using two-component nanorods as a potential theranostic in breast cancer treatment, with capabilities in dual imaging and targeted gene delivery.

• Macromolecular Research
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• 제15권4호
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• pp.348-356
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• 2007

The aim of this study was to fabricate a submicro-and micro-patterned fibronectin coated wafer for a cell culture, which allows the positions and dimensions of the attached cells to be controlled. A replica molding was made into silicon via a photomask in quartz, using E-beam lithography, and then fabricated a polydimethylsiloxane stamp using the designed silicon mold. Hexadecanethiol $[HS(CH_2){_{15}}CH_3]$, adsorbed on the raised plateau of the surface of polydimethylsiloxane stamp, was contact-printed to form self-assembled monolayers (SAMs) of hexadecanethiolate on the surface of an Au-coated glass wafer. In order to form another SAM for control of the surface wafer properties, a hydrophilic hexa (ethylene glycol) terminated alkanethiol $[HS(CH_2){_{11}}(OCH_2CH_2){_6}OH]$ was also synthesized. The structural changes were confirmed using UV and $^1H-NMR$ spectroscopies. A SAM terminated in the hexa(ethylene glycol) groups was subsequently formed on the bare gold remaining on the surface of the Aucoated glass wafer. In order to aid the attachment of cells, fibronectin was adsorbed onto the resulting wafer, with the pattern formed on the gold-coated wafer confirmed using immunofluorescence staining against fibronectin. Fibronectin was adsorbed only onto the SAMs terminated in the methyl groups of the substrate. The hexa (ethylene glycol)-terminated regions resisted the adsorption of protein. Human dermal fibroblasts (P=4), obtained from newborn foreskin, only attached to the fibronectin-coated, methyl-terminated hydrophobic regions of the patterned SAMs. N-HDFs were more actively adhered, and spread in a pattern spacing below $14{\mu}m$, rather than above $17{\mu}m$, could easily migrate on the substrate containing spacing of $10{\mu}m$ or less between the strip lines.

• Animal cells and systems
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• 제3권2호
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• pp.215-219
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• 1999

Monoclonal antibody for delta-9-tetrahydrocannabiol (THC Ab), conjugated with protein A-gold, was employed as a probe to detect THC localization in the gland and subjacent cells of chemically fixed bracts of Cannabis. THC was detected in the outer wall of the disc cells, fibrillar matrix, the surface feature of secretory vesicles, and sheath throughout development of the secretory cavity. The probe was absent from vesicles. Label was also present in anticlinal walls of disc cells and walls of dermal and mesophyll cells. Little or no THC Ab was present in disc cells and none were detected in control tissues. This distribution pattern of THC Ab was similar to that in tissues prepared by high pressure cryofixation-cryosubstitution. Consistent association of THC with wall and wall-derived materials suggests that cannnabinoids are synthesized outside the plasma membrane and bound to a wall component, where-upon they are transported to the cavity with wall materials released from the disc cell wall during development of the secretory cavity.

• 전기화학회지
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• 제13권1호
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• pp.70-74
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• 2010

전기화학 반응을 이용한 실리콘 표면상으로의 단백질 고정을 연구하였다. 이를 위해 Nitrobenzendiazonium(NiBD) 양이온을 화학적 환원반응을 통해 수식하고 수식된 실리콘 표면을 전기화학적으로 다시 환원시켜 나이트로 기능기를 일차아민 기능기로 활성화하여 단백질 고정에 이용하였다. 활성화 된 표면에 금 나노입자를 고정하여 일차 아민 생성을 확인하였다. 또한 이 방법을 응용하여 실리콘 나노선 어레이 중 선택된 나노선 만을 활성화하고 단백질을 선택적으로 고정하는 연구를 수행하였다. 이 연구를 통하여 NiBD 양이온의 화학 및 전기화학 반응이 실리콘 나노선 표면으로 단백질의 선택적 고정화에 유용하게 사용될 수 있음을 보였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.126-126
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• 2014

Label-free biomolecular assay based localized surface plasmon resonance (LSPR) of noble metal nanoparticles enables simple and rapid detection with the use of simple equipment. Nanosized metal nanoparticles exhibit a strong absorption band when the incident light frequency is resonant with the collective oscillation of the electrons, which is known as the LSPR. Here we demonstrate localized surface plasmon resonance (LSPR) substrates such as plasmonic Au nanodisks fabricated by a nanoimprinting process and gold nanorod-immobilized surfaces and their applications to highly sensitive and/or label-free biosensing. To increase detection sensitivity various bioreceptors weree designed. A single chain variable fragment (scFv) was used as a receptor to bind C-reactive protein (CRP). The results of this effort showed that CRP in human serum could be quantitatively detected lower than 1 ng/ml. Aptamers, which were immobilized on gold nanorods, were used to detect mycotoxins. The specific binding of ochratoxin A (OTA) to the aptamer was monitored by the longitudinal wavelength shift of LSPR peak in the UV-Vis spectra resulting from the changes of local refractive index near the GNR surface induced by accumulation of OTA and G-quadruplex structure formation of the aptamer. According to our results, OTA could be quantitatively detected lower than 1 nM level. Additionally, aptamer-functionalized GNR substrate was quite robust and can be regenerated many times by rinsing at 70 OC to remove bound target. During seven times of washing steps, the developed OTA sensing system could be reusable. Moreover, the proposed biosensor exhibited selectivity over other mycotoxins with an excellent recovery for detection in grinded corn samples, suggesting that the proposed LSPR based aptasensor plays an important role in label-free detection of mycotoxins.

• KSBB Journal
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• 제13권5호
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• pp.502-510
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• 1998

Stabilization of antibody, which is specific to Salmonella typhimurium antigens, present in dry states on membranes was accomplished, and its shelf-life, i.e., duration for maintaining minimum 90% of the initial activity, under optimal conditions was determined. To prepare two major components of an immuno-strip, the antibody was not only immobilized on nitrocellulose membrane surfaces but also placed within the pores of glass fiber membrane after conjugating it with old colloids as signal generator. Among potential stabilizers of the immuno-components, a disaccharide, trehalose, showed a significant protection effect of immunoglobulin structure from thermal energy. Optimal concentrations of trehalose for the respective component were significantly different (8-fold higher for the antibody-gold conjugate than for the immobilized antibody), which probably resulted from distinct densities and configurations of antibody present on the membranes. An additional requirement for the gold conjugate was freeze-drying of this substance such that the conjugate can be readily resolubilized upon contact with aqueous medium. By using the components prepared under optimal conditions, immuno-strips were constructed and exposed to thermal energy. Signals with less than 10% decrease in the intensity were maintained for approximately 21 days at 60$^{\circ}C$. Compared to previous reports, this result represented a 2-year shelf-life at room temperature. it was, however, two times longer if determined from thermal acceleration tests based on the theory of inactivation rate of protein. Such discrepancy between the two estimates could be mainly attributed to errors in accurately controlling temperatures and also to changes in the physical properties of membranes due to a high thermal energy.