• Current Applied Physics
• /
• v.18 no.11
• /
• pp.1294-1299
• /
• 2018

In this paper, we demonstrate the feasibility of constructing DNA nanostructures (i.e. DNA rings and double-crossover (DX) DNA lattices) with appropriate doxorubicin hydrochloride (DOX) concentration and reveal significant characteristics for specific applications, especially in the fields of biophysics, biochemistry and medicine. DOX-intercalated DNA rings and DX DNA lattices are fabricated on a given substrate using the substrateassisted growth method. For both DNA rings and DX DNA lattices, phase transitions from crystalline to amorphous, observed using atomic force microscopy (AFM) occurred above a certain concentration of DOX (at a critical concentration of DOX, $30{\mu}M$ of $[DOX]_C$) at a fixed DNA concentration. Additionally, the coverage percentage of DNA nanostructures on a given substrate is discussed in order to understand the crystal growth mechanism during the course of annealing. Lastly, we address the significance of optical absorption and photoluminescence characteristics for determining the appropriate DOX binding to DNA molecules and the energy transfer between DOX and DNA, respectively. Both measurements provide evidence of DOX doping and $[DOX]_C$ in DNA nanostructures.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2003.05a
• /
• pp.83-86
• /
• 2003

Major advances in positive-sense RNA virus research have been facilitated by the development of reverse genetics systems. These systems consist of an infectious cDNA clone that encompasses the genome of the virus in question. This clone is then used as a template for the subsequent synthesis of infectious RNA for the generation of synthetic viruses. However, the construction of infectious cDNA for the Japanese encephalitis virus (JEV) has been repeatedly thwarted by the instability of its cDNA. As JEV is an important human pathogen that causes permanent neuropsychiatric sequelae and even fatal disease, a reliable reverse genetics system for this virus is highly desirable. The availability of this tool would greatly and the development of effective vaccines as well as facilitate studies into the basic biology of the virus, including the molecular mechanisms of viral replication, neurovirulence, and pathogenesis. We have successfully constructed a genetically stable infectious JEV cDNA containing full-length viral RNA genome. Synthetic RNA transcripts generated in vitro from the cDNA were highly infectious upon transfection into susceptible cells, and the cDNA remained stable after it had been propagated in E. coli for 180 generations. Using this infectious JEV cDNA, we have successfully expressed a variety of reporter genes from the full-length genomic and various subgenomic RNAs in vitro transcribed from functional JEV cDNAS. In summary, we have developed a reverse genetics system for JEV that will greatly facilitate the research on this virus in a variety of different fields. It will also be useful as a heterologous gene expression vector and aid the development of a vaccine against JEV.

• The Journal of Korean Society for Radiation Therapy
• /
• v.4 no.1
• /
• pp.71-77
• /
• 1990

The present study was undertaken to investigate effects of ionizing radiation on DNA synthesis and chromosomal abnormality in cultured submandibular gland(SG) cells. SG cells from C57BL/6N Crj mice were cultured in Dulbecco's modified Eagle's medium (DME) supplemented with $10\%$ fetal bovine serum, antibiotics and fungizone. The cultured SG cells were irradiated with graded doses of gamma ray ($^{60}Co$) at a dose rate of 58.4rad/min. The effect of irradiation of $^{60}Co$ on DNA synthesis in cultured cells was evaluated by measuring the incorporation of 3H-TdR. Using conventional chromosome techniques and Giemsa staining methods, chromosomal abnormalities in cultured SG cells, induced by irradiation of $^{60}Co$ werw examined. Cytological observations were carried out by a light microscope with high resolving power. The results obtained were as follows : 1. DNA synthesis of SG cells was quantitatively dependent on a radiation dose compare to control. 2. A polyploids and few chromosome-type break, such as single and double breaks, deltions and triradial figures were more predominantly in irradiated SG cells than in control. This increase of chromosomal abnormality was in the proposition to the irradiation doses.

• Korean Journal Plant Pathology
• /
• v.10 no.3
• /
• pp.228-234
• /
• 1994

Genomic RNA was extracted from Cy strain of odontoglossum ringspot tobamovirus (ORSV-Cy) isolated from infected leaves of tobacco cv. Samsun. Size of the genomic RNA was about 6.6 kb in length. The genomic RNA was fractionated using Sephadex G-50 column chromatography into 2 fractions. They were polyadenylated at their 3'-end using E. coli poly(A) polymerase. Polyadenylated viral RNA was recovered by oligo (dT) primer adapter containing NotI restriction site and Moloney murine leukemia virus SuperScript reverse transcriptase (RNase H-). Second-strand cDNA was synthesized by using E. coli DNA ligase, E. coli DNA polymerase I and E. coli RNase H. Recombinant plasmids containing cDNAs for ORSV-Cy RNA ranged from about 800 bp to 3,000 bp. Among the selected 238 recombinants, pORCY-124 clone was the largest one covering 3'-terminal half of the viral RNA. This clone contained two restriction sites for EcoRI and XbaI and one site for AccI, AvaI, BglII, BstXI, HindIII, PstI, and TthIII 1. respectively. The clone contained partial viral replicase, a full-length movement protein and a complete coat protein genes followed by a 3' untranslated region of 414 nucleotides based on restriction mapping and nucleotide sequencing analyses. Clones pORCY-028, -068, -072, -187 and -224 were overlapped with the pORCY-124. Clones pORCY-014 and -095 covered 5' half upstream from the middle region of the viral RNA, which was estimated based on restriction mapping and partial sequence analysis. Constructed cDNA library covered more than 90% of the viral genome.

• 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.

• Korean Journal of Microbiology
• /
• v.25 no.2
• /
• pp.103-109
• /
• 1987

An ozone-sensitive mutant of Escherichia coli strain B, MQ 1844 is described. Its properties, including high sensitivity to ozone and radiation, inducible filamentation, extensive DNA degradation and impaired DNA synthesis following ozonation, are attributable to a mutation in ozrB, a gene which is cotransducible with malB. Based on differences in phenotypic expression as well as on the particular location of this gene on the bacterial chromosome, ozrB appears as distinct from the other ozone-or radiation-sensitivity genes previously described.

• The Korean Journal of Mycology
• /
• v.22 no.4
• /
• pp.366-377
• /
• 1994

The base composition of DNA of Aspergillus phoenicis, Rhizopus acidus and Candida albicans treated with cycloheximide and nalidixic acid during the culture was analyzed to compare with the control. The contents of base in the DNA were inhibited by cycloheximide, 20.4% of adenine, 43.1% of thymine, 40.9% of cytosine, 35.3% of guanine, 32.2% of purine, and 42.7% of pyrimidine for A. phoenicis. In R. acidus, 34.2% of adenine, 42.1% of thymine, 38.0% of cytosine, 18.1% of guanine, 24.1% of purine and 40.0% of pyrimidine were depressed by cycloheximide. In the antibiotic treatment of C. albicans, 58.3% of adenine, 58.5% of thymine, 58.1% of cytosine, 42.4% of guanine, 46.8% of purine and 58.8% of pyrimidine were inhibited to compare with the control. The nalidixic acid treatments were showed that, in A. phoenicis 41.6% of adenine, 47.1% of thymine, 59.3% of cytosine, 46.3% of guanine, 45.6% of purine and 57.2% of pyrimidine were inhibited. When R. acidus was treated with nalidixic acid, 59.1% of adenine, 54.7% of thymine, 35.3% of cytosine, 37.4% of guanine, 45.9% of purine and 44.9% of pyrimidine decreased. In treatment of nalidixic acid, the content of DNA was depressed 60.1% of adenine, 68.6% of thymine, 60.7% of cytosine, 40.0% of guanine, 45.8% of purine and 63.5% of pyrimidine for C. albicans In the DNA synthesis of three fungal cells, cycloheximide and nalidixic acid treatments were analyzed obviously that the biosynthesis of pyrimidine was depressed than that of purine. Therefore, it was showed that the DNA contents in the various fungal cells were inhibited remarkably in nalidixic acid treatment than cycloheximide.

• The Korean Journal of Pharmacology
• /
• v.25 no.1
• /
• pp.115-134
• /
• 1989

Combined effects of ganciclovir (GCV) and vidarabine (ara-A) on the replication, DNA synthesis, and gene expression of wild type-1 herpes simplex virus (HSV-1) and three acyclovir (ACV)-resistant HSV-1 mutants were studied. These mutants include a virus expressing no thymidine kinase $(ACV^r)$, a virus expressing thymidine kinase with altered substrate specificity $(IUdR^r)$, and a mutant expressing altered DNA polymerase $(PAA^r5)$. GCV, an agent activated by herpesvirus specific thymidine kinase, showed potent antiviral activity against the wild type HSV-1(KOS) and DNA polymerase mutant $(PAA^r5)$. The ACV-resistant mutants with thymidine kinase gene $(ACV^r\;and\;IUdR^r)$ were resistant to GCV. All tested wild type HSV-1 or ACV-resistant HSV-1 mutants did not display resistance to vidarabine (are-A). Combined GCV and ara-A showed potentiating synergistic antiviral activity against wild type KOS and $PAA^r5$, and showed subadditive combnined ativiral activity against thymidine kinase mutants. Combined GCV and ara-A more significantly inhibited the viral DNA synthesis in wild type KOS and $PAA^r5-infected$ cells to a greater extent than either agent alone, but the synergism was not determined in $ACV^r$ or $IUdR^r-infected$ cells. These data clearly indicate that combined GCV and ara-A therapy might be useful for the treatment of infections caused by wild type HSV-1 or ACV-resistant HSV-1 with DNA polymerase mutation. ACV-resistant viruses with the mutation in thymidine kinase gene are also, resistant to GCV, but susecptible to ara-A, indicating that ara-A would the drug of choice for the treatment of ACV-resistant HSV-1 which does not express thymidine kinase or expresses thymidine kinase with altered substrate specificity. While the synthesis of viral ${\alpha}-proteins$ of wild type HSV-1 was not affected by ACV, GCV, ara-A, or combined GCV and ara-A, the synthesis of ${\beta}-proteins$ was slightly but significantly increased at the later stage of viral infection by the antiviral agents. The synthesis of ${\gamma}-proteins$ of wild type HSV- 1 was significantly inhibited by ACV, GCV, ara-A, and combined GCV and ara-A. Combined GCV $(5-{\mu}M)$ and ara-A $(100-{\mu}M)$ also significantly altered the expression of viral ${\beta}-and$ ${\gamma}-proteins$, of which efffct was similar to that of GCV $(10-{\mu}M)$ alone. Although ACV at the concentration of $10-{\mu}M$ did not alter the expression of ${\alpha}-$, ${\beta}-$, and ${\gamma}-proteins$ of ACV-resistant $PAA^r5$, GCV and ara-A significantly alter the epression of ${\beta}-and$ ${\gamma}-proteins$, not ${\alpha}-protein$, as same manner as they altered the expression of those proteins in cells inffcted with wild type HSV-1. Combined GCV $(5-{\mu}M)$ and ara-A $(100-{\mu}M)$ altered the expression ${\beta}-and$ ${\gamma}-proteins$ in $PAA^r5$ infected cells, and the effect of combined regimen was comparable of that of GCV $(10-{\mu}M)$. These data indicate that the alteration in the expression of ${\beta}-and$ ${\gamma}-proteins$ in wild type HSV-1 or $PAA^r5$ infected cells could be more significantly affected by combined GCV and are-A than individual GCV or ara-A. In view of the fact that (a) viral ${\alpha}-$, ${\beta}-$, and ${\gamma}-proteins$ are synthesized in a cascade manner; (b) ${\beta}-proteins$ are essential for the synthesis of viral DNA; (c) the synthesis of ${\beta}-proteins$ are inhibited by ${\gamma}-proteins$; and (d) most ${\gamma}-proteins$ are made from the newly synthesized progeny virus, it is suggested that GCV and ara-A, alone or in combination, primarily inhibit the synthesis of viral DNA, and by doing so might exhibit their antiherpetic activity. The alteration in viral protein synthesis in the presence of tested antiviral agents could result from the alteration in viral DNA synthesis. From the present study, it can be concluded that (a) combined GCV and ara-A therapy would be beneficial for the control of inffctions caused by wild type HSV-1 or ACV-resistant DNA polymerase mutants; (b) the combined synergistic activity of GCV and ara-A is due to further decrease in the viral DNA by the combined regimen; (c) ara-A is the drug of choice for the infection caused by ACV-resistant HSV-1 with thymidine kinase mutation; and (d) the alteration in viral protein synthesis by GCV and ars-A, alone or in combination, is mostly due to the decreased synthesis of viral DAN.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.3
• /
• pp.275-282
• /
• 1993

The objective of this study was to clone a partial fragment of $\alpha$-amylase from Korean maize. We designed and synthesized an oligonucleotide probe and two kinds of PCR primers based on cDNA conserved region of $\alpha$-amylase sequences from other plants. Total RNA from 3-day-old maize seedling was used as template for 1st strand cDNA synthesis and RNA-DNA hybrid was used as template for polymerase chain reaction(PCR). The product of PCR was about 0.5 kb long and inserted into pUC19. We named this recombinant plasmid as pZM$\alpha$'. The cloned fragment was certified by Southern blot analysis using labeled synthetic oligonucleotide as probe.

• The Korean Journal of Physiology
• /
• v.8 no.1
• /
• pp.23-26
• /
• 1974

It was planned to evaluate the influence of Panax Ginseng upon DNA synthesis of submandibular gland in mice by observing incorporation of $[^3H]$ thymidine into the tissue cells. Thirty male mice $(body\;weight:\;18{\sim}20\;g)$ were divided equally into two groups. One group received every day (subcutaneously) 0. 05 ml/10 g body weight of ginseng extract(4 mg of ginseng alcohol extract in 1ml of saline), while !he other group received the same amount of saline, for 5 days. On the 5th experimental day, all animals received $1\;{\mu}Ci/g$ body weight of $[^3H]$ thymidine intraperitoneally 2 hours after the last medication. Five animals, at a time, of each group were sacrificed 1, 10, and 24 hours after $[^3H]$ thymidine administration, and the radioactivity of cells in their mandibular gland was measured autoradiographically in terms of the % number of radioactive cells in 1,000 tell counts (Radioactive Index, R.I.). It was found that the radioactive indices of mice that received ginseng were lower than the corresponding values of mice that received saline. The inference from the above result was that the ginseng suppressed DNA synthesis of cells in the mandibular gland.