• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.6
• /
• pp.560-570
• /
• 2005

In this paper, a microelectrode away DNA chip was fabricated on glass slide using photolithography technology. Several probe DNAs consisting of mercaptohexyl moiety at their 5' end were immobilized on the gold electrodes by DNA arrayer utilizing the affinity between gold and sulfu. Then target DNAs were hybridized and reacted with Hoechst 33258, which is a DNA minor groove binder and electrochemically active dye. Cyclic voltammetry in 5mA ferricyanide/ferrocyanide solution at 100 mV/s confirmed the immobilization of probe DNA on the gold electrodes. Linear sweep voltammetry or cyclic voltammetry showed a difference between target DNA and control DNA in the anodic peak current values. It was derived from Hoechst 33258 concentrated at the electrode surface through association with formed hybrid. It suggested that this DNA chip could recognize the sequence specific genes. It suggested that multichannel electrochemical DNA microarray is useful to develop a portable device for clinical gene diagnostic system.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.8
• /
• pp.2923-2943
• /
• 2021

The double helix structure of DNA makes it diverse, stable and can store information with high density, and these characteristics are consistent with the requirements of molecular communication for transport carriers. In this paper, a specific structure of molecular communication system based on DNA length coding is proposed. Transmitter (Tx) adopts the multi-layer golden foil design to control the release of DNA molecules of different lengths accurately, and receiver (Rx) adopts an effective and sensitive design of nanopore, and the biological information can be converted to the electric signal at Rx. The effect of some key factors, e.g., the length of time slot, transmission distance, the number of releasing molecules, the priori probability, on channel capacity is demonstrated exhaustively. Moreover, we also compare the transmission capacity of DNA-based molecular communication (DNA-MC) system and concentration-based molecular communication (MC) system under the same parameter setting, and the peak value of capacity of DNA-MC system can achieve 0.08 bps, while the capacity of MC system remains 0.025 bps. The simulation results show that DNA-MC system has obvious advantages over MC system in saving molecular resources and improving transmission stability.

• Molecules and Cells
• /
• v.45 no.1
• /
• pp.33-40
• /
• 2022

The various DNA-protein interactions associated with the expression of genetic information involve double-stranded DNA (dsDNA) bending. Due to the importance of the formation of the dsDNA bending structure, dsDNA bending properties have long been investigated in the biophysics field. Conventionally, DNA bendability is characterized by innate averaging data from bulk experiments. The advent of single-molecule methods, such as atomic force microscopy, optical and magnetic tweezers, tethered particle motion, and single-molecule fluorescence resonance energy transfer measurement, has provided valuable tools to investigate not only the static structures but also the dynamic properties of bent dsDNA. Here, we reviewed the single-molecule methods that have been used for investigating dsDNA bendability and new findings related to dsDNA bending. Single-molecule approaches are promising tools for revealing the unknown properties of dsDNA related to its bending, particularly in cells.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.12 no.4
• /
• pp.305-309
• /
• 1983

The effect of the nucleic acid related compounds, amino acids and ureas on the breakage of calf thymus DNA were investigated with or without inorganic salts. PTU and Cys-SH possessed the ability of DNA strand breaks without metal ions. Tyr, Phe and Trp induced a weak DNA lesions in the presence of $CuSO_4$. Cys-SH with concentrations of 5mM in the presence of metal ion, $CuSO_4$, showed the strong ability to break the DNA. Various metal solutions($500{\mu}M$) except $Sn^{2+}$ did not show the DNA-breaking action. The DNA strands were damaged by some amino acids in the presence of $Cu^{2+}$, $Ni^{2+}$, $Mn^{2+}$, $Zn^{2+}$ and $Sn^{2+}$.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.6 no.1
• /
• pp.87-92
• /
• 2003

We describe here the cloning, expression and characterization of a cDNA encoding a putative chemosensory protein (CSP) from the mole cricket, Gryllotalpa orientalis. The G. orientalis chemosensory protein cDNA sequences comprised of 384 bp with 128 amino acid residues. The G. orientalis chemosensory protein showed 75.4% protein sequence identity to the Locusta migratoria CSP, Northern blot analysis revealed that signal was stronger in head than leg and cuticle, indicating that the head part containing antennae is a main site for G. orientalis chemosensory protein synthesis. The cDNA encoding G. orientalis chemosensory protein was expressed as approximately 12 kDa polypeptide in baculovirus-infected insect cells.

• Journal of Plant Biotechnology
• /
• v.2 no.3
• /
• pp.115-121
• /
• 2000

A cDNA clone encoding chloroplast triosephosphate isomerase (TPI-cp) was isolated from strawberry fruit cDNA library. Sequence analyses indicated that the cDNA contains an open reading frame of 314 amino acids (33.5 kDa) composed of a transit peptide (59 amino acids) in amino terminal region and mature protein (255 amino acids). The existence of transit peptide in the deduced amino acid sequence implies that it encodes a chloroplast isoform. The protein sequence is more similar to other plant chloroplast isoforms than cytosolic isoforms. RNA blot analysis indicated that its expression is ubiquitous in examined five tissues, flowers, leaves, petioles, roots and fruits, and shows differential pattern according to fruit ripening. Genomic DNA blot analysis showed that TPI-cp is encoded by multiple genes in strawberry. Through sequence comparison and phylogenetic tree construction, TPI-cp is distinctively grouped into dicot and chloroplast isoforms.

• Preventive Nutrition and Food Science
• /
• v.7 no.3
• /
• pp.323-326
• /
• 2002

Ionizing radiation can be used to sanitize herbs contaminated by various microorganisms. However, health concerns related to irradiation damage to complex molecules in plants necessitate that methods be developed to monitor such damage. To elucidate DNA damage of herbs caused by irradiation, the DNA comet assay was used for Astragalus membranaceus Bunge and Havenia dulcis Thumb, irradiated at 1, 5, 7, and 10 kGy. With increasing irradiation doses, the tails of comets became longer with average tail length increasing from 17 (non-irradiated) to 124 (10 kGy) $\mu$m in Astragalus membranaceus Bunge. Above 7 kGy, some of the tails were separated from the heads of comets. Distribution patterns of the tail length of In comets selected randomly in the irradiated herbs were analyzed to quantify the DNA damage. These results clearly suggest that the DNA comet assay is an effective and inexpensive tool for the detection of irradiation damage to DNA in herbs.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.05a
• /
• pp.497-498
• /
• 2000

The venus clam, Ruditapes philippinarum, is an aquaculture shellfish mainly distributed in an intertidal zone of East Asia including Korea, China and Japan. The morphological variation of this species is great. In fact, two of the most popular markers used in molecular evolution, mitochondrial DNA (mtDNA) and nuclear ribosomal DNA (rDNA), have quite different properties, which could translate into different consequences of mutation, drift, migration and selection on patterns of geographical variation and molecular divergence. (omitted)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.05a
• /
• pp.65-70
• /
• 2006

In this study, a DNA chip with a microelectrode array was fabricated using microfabrication technology. Several probe DNAs consisting of mercaptohexyl moiety at their 5 end were immobilized on the gold electrodes by DNA arrayer. Then target DNAs were hybridized and reacted with Hoechst 33258, which is a DNA minor groove binder and electrochemically active dye. Linear sweep voltammetry or cyclic voltammetry showed a difference between target DNA and control DNA in the anodic peak current values. It was derived from Hoechst 33258 concentrated at the electrode surface through association with formed hybrid. It suggested that this DNA chip could recognize the sequence specific genes.

• Journal of Radiation Protection and Research
• /
• v.43 no.2
• /
• pp.66-74
• /
• 2018

Background: Tumor response to anticancer therapies can much be influenced by microenvironmental factors. In this study, we determined the effect of these microenvironmental factors on DNA methylation using A549 human lung adenocarcinoma cell line. Materials and Methods: We subjected A549 cells to various conditions mimicking tumor microenvironment including hypoxia, acidosis (sodium lactate), oxidative stress ($H_2O_2$), bystander effect (supernatant from doxorubicin (Dox)-treated or irradiated cells), and immune cell infiltration (supernatant from THP-1 or Jurkat T cells). Genomic DNA was isolated from these cells and analyzed for DNA methylation. Clonogenic cell survival, gene expression, and metabolism were analyzed in cells treated with some of these conditions. Results and Discussion: We found that DNA methylation level was significantly decreased in A549 cells treated with conditioned media from Dox-treated cells or Jurkat T cells, or sodium lactate, indicating an active transcription. To determine whether the decreased DNA methylation affects radiation sensitivity, we exposed cells to these conditions followed by 6 Gy irradiation and found that cell survival was significantly increased by sodium lactate while it was decreased by conditioned media from Dox-treated cells. We further observed that cells treated with conditioned media from Dox-treated cells exhibited significant changes in expression of genes including BAX and FAS (involved in apoptosis), NADPH dehydrogenase (mitochondria), EGFR (cellular survival) and RAD51 (DNA damage repair) while sodium lactate increased cellular metabolism rather than changing the gene expression. Conclusion: Our results suggest that various tumor microenvironmental factors can differentially influence DNA methylation and hence radiosensitivity and gene expression in A549 cancer cells.