• 대한수의학회지
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• 제42권2호
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• pp.209-217
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• 2002

This study was performed to produce monoclonal antibodies (mAb) specifically reacting with chicken leukocyte surface antigens. Popliteal lymph node cells of BALB/c mice previously immunized through foot-pad with peripheral blood mononuclear cells (PBMC) of chickens separated by Ficoll-Histopaque method. They were fused with P3X63Ag14 mouse myeloma cells. A total of 34 hybridomas secreted antibodies specifically binding to the PBMC. According to the reactivity patterns with PBMC, the mAbs were divided into 4 groups. Group 1 mAbs (IIB3, IIB10, IIE10) specifically reacted with non-adherent lymphocytes but not with adherent cells which were mainly composed of thrombocytes and monocytes in PBMC culture. These mAbs were reactive with 25-59% of thymus cells and 42-64% of spleen cells of chickens. They did not show any significant reactivity with cells in the bursa of Fabricius, T-cell (MDCC-MSB1) and B-cell (LSCC-1104B1) lines. These results indicate that Group I mAbs specifically reacted with T-lymphocyte subpopulation. Monoclonal antibodies in Group II (IC6, IG2-2 and IID9) showed specific reactivity with monocytes but not with thrombocytes or non-adherent cells in PBMC culture. These mAbs, though not reacted with the chicken macrophage cell line, HD11, also bound to macrophages of the spleen and lung in immunohistochemical staining. Five mAbs in Group III showed characteristics of binding to lymphocytes and monocytes, but not to thrombocytes. Twenty-three mAbs in Group IV showed specific reactivity to lymphocytes, monocytes, and thrombocytes. Two mAbs (IC3 and IE9) in Group IV reacted with most of PBMC.

• KSBB Journal
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• 제17권1호
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• pp.20-25
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• 2002

We performed a basic experiment for rapid, on-line, real-time measurement of HBsAg by using a surface plasmon resonance biosensor to quantify the recognition and interaction of biomolecules. We immobilized the anti-HBsAg polyclonal antibody to the dextran layer on a CM5 chip surface which was pre-activated by N-hydroxysuccinimide for amine coupling. The binding of the HBsAg to the immobilized antibody was measured by the mass increase detected by the change in the SPR signal. The binding characteristics between HBsAg and its antibody followed typical monolayer adsorption isotherm. When the entire immobilized antibody was interacted, there was no additional, non-specific binding observed, which suggested the biointeraction was very specific as expected and independent of the ligand density. No significant steric hindrance was observed at 17.6 nm/$mm^2$ immobilization density. The relationship between the HBsAg concentration in the sample solution and the antigen bound to the chip surface was linear up to ca. $40\mu\textrm{g}$/mL, which is much wider than that of the ELISA method. It appeared the antigen-antibody binding was increased as the immobilized ligand density increased, but verification is warranted. This study showed the potential of this biosensor-based method as a rapid, simple, multi-sample, on-line assay. Once properly validated, it can serve as a more powerful method for HBsAg quantification replacing the current ELISA method.

• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.541-549
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• 2015

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with higher metastatic rate and both local and systemic recurrence compared to non-TNBC. The generation of reactive oxygen species (ROS) secondary to oxidative stress is associated with DNA damage, chromosomal degradation and alterations of both hypermethylation and hypomethylation of DNA. This study concerns differential methylation of promoter regions in specific groups of genes in TNBC and non-TNBC Saudi females in an effort to understand whether epigenetic events might be involved in breast carcinogenesis, and whether they might be used as markers for Saudi BCs. Methylation of glutathione S-transferase P1 (GSTP1), T-cadherin (CDH13), Paired box protein 5 (PAX5), death associated protein kinase (DAPK), twist-related protein (TWIST), DNA-binding protein inhibitor (ID4), High In Normal-1 (HIN-1), cyclin-dependent kinase inhibitor 2A (p16), cyclin D2 and retinoic acid receptor-${\beta}$ ($RAR{\beta}1$) genes was analyzed by methylation specific polymerase chain reaction (MSP) in 200 archival formalin-fixed paraffin embedded BC tissues divided into 3 groups; benign breast tissues (20), TNBC (80) and non-TNBC (100). The relationships between methylation status, and clinical and pathological characteristics of patients and tumors were assessed. Higher frequencies of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 hypermethylation were found in TNBC than in non-TNBC. Hypermethylation of GSTP1, CDH13, ID4, DAPK, HIN-1 and PAX5 increased with tumor grade increasing. Other statistically significant correlations were identified with studied genes. Data from this study suggest that increased hypermethylation of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 genes in TNBC than in non-TNBC can act as useful biomarker for BCs in the Saudi population. The higher frequency of specific hypermethylated genes paralleling tumor grade, size and lymph node involvement suggests contributions to breast cancer initiation and progression.

• International Journal of Industrial Entomology and Biomaterials
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• 제26권1호
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• pp.31-40
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• 2013

Paralytic peptide binding proteins (PP-BP) are 30KP proteins that show similarity to ENF binding proteins. The ENF-BP act as active regulators of ENF peptides. ENF peptides are multifunctional insect cytokines. The comparison of gene expression in diapause induced and non-diapause eggs at different time intervals after oviposition showed an upregulation of PP at 18h as well as PP-BP at 12 and 18h after oviposition along with few other genes. The current study has been taken up to investigate the role of PP as well as PP-BP in diapause induction in polyvoltine silkworms and to study the multigene organization of PP-BP in the Bombyx mori genome. The tissue specific expression analysis revealed that, PP-BP is highly expressed in fat body followed by egg and brain while no expression was observed in midgut. The expression levels of PP and PP-BP in diapause and non-diapause eggs from 0h to 48h after oviposition, validated through realtime PCR revealed that PP is highly expressed at 18 and 24h while PP-BP expression is higher at 12 and 18h time intervals suggesting their possible role in diapause induction. The whole genome survey of the PP-BP paralogous sequences revealed a total of 46 B. mori PP-BP homologs that are classified into 3 categories viz., ENF-BP, Typical 30KPs and serine/threonine rich 30KPs. These paralogous sequences are distributed on chromosomes 7, 20, 22 and 24, all 30KP and S/T rich 30KP proteins are present in the same locus of chromosome 20.

• BMB Reports
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• 제50권4호
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• pp.158-159
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• 2017

MicroRNAs (miRNAs) regulate gene expression by guiding the Argonaute (Ago)-containing RNA-induced silencing complex (RISC) to specific target mRNA molecules. It is well established that miRNAs are stabilized by Ago proteins, but the molecular features that trigger miRNA destabilization from Ago proteins remain largely unknown. To explore the molecular mechanisms of how targets affect the stability of miRNAs in human Ago (hAgo) proteins, we employed an in vitro system that consisted of a minimal hAgo2-RISC in HEK293T cell lysates. Surprisingly, we found that miRNAs are drastically destabilized by binding to seedless, non-canonical targets. We showed that miRNAs are destabilized at their 3' ends during this process, which is largely attributed to the conformational flexibility of the L1-PAZ domain. Based on these results, we propose that non-canonical targets may play an important regulatory role in controlling the stability of miRNAs, instead of being regulated by miRNAs.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.378.2-378.2
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• 2016

Biosensors currently suffer from severe non-specific adsorption of proteins, which causes false positive errors in detection through overestimation of the affinity value. Overcoming this technical issue motivates our research. Polyethylene glycol (PEG) is well known for its ability to reduce the adsorption of biomolecules; hence, it is widely used in various areas of medicine and other biological fields. Likewise, amine functionalized surfaces are widely used for biochemical analysis, drug delivery, medical diagnostics and high throughput screening such as biochips. As a result, many coating techniques have been introduced, one of which is plasma polymerization - a powerful coating method due to its uniformity, homogeneity, mechanical and chemical stability, and excellent adhesion to any substrate. In our previous works, we successfully fabricated plasmapolymerized PEG (PP-PEG) films [1] and amine functionalized films [2] using the plasma enhanced chemical vapor deposition (PECVD) technique. In this research, an amine functionalized PP-PEG film was fabricated by using the plasma co-polymerization technique with PEG 200 and ethylenediamine (EDA) as co-precursors. A biocompatible amine functionalized film was surface characterized by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The density of the surface amine functional groups was carried out by quantitative analysis using UV-visible spectroscopy. We found through surface plasmon resonance (SPR) analysis that non-specific protein adsorption was drastically reduced on amine functionalized PP-PEG films. Our functionalized PP-PEG films show considerable potential for biotechnological applications such as biosensors.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.31-32
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• 2006

We describe the preparation of nanostructured molecularly-imprinted surfaces using nanomolding on porous alumina. In molecular imprinting functional and cross-linking monomers are copolymerized in the presence of a molecular template, resulting in synthetic receptor materials. The drug propranolol and the dye fluorescein were used as the molecular imprinting templates. Binding studies with imprinted and non-imprinted surfaces revealed specific recognition of the templates and thus the existence of selective binding sites. In addition, the surface properties of the films were studied by water contact angle measurements. It was found that, depending on the monomers used, certain nanostructures induced great changes in the wetting properties of the surface.

• 약학회지
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• 제45권3호
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• pp.302-309
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• 2001

Wheat germ agglutinin (WGA) pectin, which binds to human melanoma cell line, was conjugated with Praecoxin A using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as a cross-linking agent. Physical mixture (PM) of WGA and Praecoxin A was also prepared by using a non-specific binding property of Praecoxin A to WGA. The WGA:Praecoxin A ratio in the conjugate and PM was approximately 1:18 and 1:20, respectively. The results of hemagglutination assay and enzyme-linked lectin assay indicated that the conjugate and PM maintained the lectin-like properties of the WGA. The binding ratio of conjugate was about 70% during 4-24 hr, but the most of Praecoxin A was released within 24 hr in the case of PM. These results lead to the conclusion that the conjugate is potentially useful for the formulation of injection that requires targeting for melanoma as well as sustained release at the site.

• 생명과학회지
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• 제17권11호
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• pp.1587-1592
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• 2007

Locus control region (LCR) is a cia-acting element which regulates the transcription of genes in developmental stage and/or tissue-specific pattern. Typically, LCR consists of several DNase I hypersensitive sites (HSs), where the binding motifs for transcriptional activators are present. The binding of activators to the HSs recruits chromatin modifying complexes to the LCR, opening chromatin structure and modifying histones covalently through the locus. LCR forms close physical contact with target gene located at a distance by looping away intervening region. In addition, non-coding RNA is transcribed from LCR toward target genes in continuously acetylated active domain. These structural and functional features of LCR suggest that the LCR plays many roles in chromatin activation and transcriptional regulation.

• KSBB Journal
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• 제13권4호
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• pp.337-342
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• 1998

Immunosensor for the determination of LDL(Low-Density Lipoprotein), a good indicator for the diagnosis of atherosclerosis and hypercholesterolemia, was developed by using quartz crystal microbalance(QCM). The immunosensor consists of flow-through cell, oscillating circuit, oscilloscope, and frequency counter. FIA(Flow Injection Analysis) was applied to the QCM system for the measurement of LDL in liquid phase. Antibody showing binding affinity against LDL was immobilized on the gold electrode of a quartz crystal by covalent coupling via polyethylenimine / glutaredehyde. LDL was injected and bound to the antibody immobilized on the QCM immunosensor. The response of the immunosensor (F0 - F1) was found to be proportional to the LDL concentration from 200 $\mu\textrm{g}$/ml to 800 $\mu\textrm{g}$/ml. Operational conditions for the operation of immunosensor were also investigated in terms of sensitivity and non-specific binding.