• Molecules and Cells
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• 제23권2호
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• pp.239-245
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• 2007

DnaK is a major antigen in Streptococcus pneumoniae, and is induced by a minor shift in temperature (30 to $37^{\circ}C$) but not by ethanol shock. Although HrcA in the presence of $Ca^{{+}{+}}$ represses the expression of both groEL and hrcA, the control of transcription of the dnaK operon is not completely understood. In this study, the dnaK operon of S. pneumoniae (5' hrcA-grpE-dnaK-dnaJ) was cloned and analyzed. It contains large intergenic regions in grpE/dnaK and dnaK/dnaJ. Pulse labeling with [$^{35}S$]-methionine and immunoblot analyses revealed the presence of higher levels of DnaK than of HrcA even in the presence of $Ca^{{+}{+}}$ after heat shock suggesting that $Ca^{{+}{+}}$ differentially regulates the heat shock responses of hrcA and dnaK. By blocking de novo mRNA synthesis with rifampin it was shown that neither the hrcA nor the groEL transcripts were stabilized by heat shock even though dnaK transcripts were stabilized. We conclude that S. pneumoniae uses fine regulation of the transcription of the individual genes of the tetracistronic dnaK operon to cope with the various stresses experienced during infections.

• Current Applied Physics
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• 제18권11호
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• pp.1294-1299
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• 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.

• 생약학회지
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• 제24권2호
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• pp.159-165
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• 1993

The studies were conducted to investigate the effect of Sinhyo-Taklee-San(STS), which is composed of Astragali Radix(AR), Lonicerae Flos(LF), Angelicae gigantis Radix(AGR) and Glycyrrhizae Radix(GR), on the proliferation of fibroblast cell(Balb/c 3T3). STS, GR and glycyrrhizin increased the proliferation of 3T3 cells. The 10% serum obtained from STS, AR, LF, AGR and GR treated mice also increased the proliferation of 3T3 cells markedly. GR, glycyrrhizin and glycyrrhetinic acid inhibited protein synthesis, but did not affect on DNA synthesis.

• 미생물학회지
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• 제25권2호
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• pp.103-109
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• 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.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2769-2772
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• 2009

• 생명과학회지
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• 제19권5호
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• pp.639-643
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• 2009

배추는 재배 온도에 따라 수확량과 품질에 많은 영향을 받을 수 있다. 고온 스트레스 저항성 배추품종 육성을 위해 본 연구는 스트레스 저항성에 관련이 있다고 알려진 trehalose 유전자 관련 다형성 마커를 개발하였다. 아라비돕시스 trehalose 합성 유전자와 유사한 총 28개의 배추 EST를 NCBI database에서 찾고 고온에 상대적으로 약한 지부품종과 고온에 잘 견디는 품종인 권심을 대상으로 다형성을 조사하였다. 이 중 10개의 EST에서 insertion/deletion 또는 single nucleotide polymorphism을 발견하여 이를 바탕으로 쉽게 이용이 가능한 10개의 다형성 PCR 마커를 개발하였다. 본 연구에서 개발된 trehalose 분자마커는 앞으로 배추 작물에서 환경 스트레스 저항성과 유전적 연관성을 확인하는데 이용될 수 있고 MAS를 이용한 품종육성에 이용될 수 있다고 기대된다.

• BMB Reports
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• 제42권6호
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• pp.373-379
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• 2009

5-Hydroxyuridine (5-OHU) is a major lesion of uridine and cytosine produced in RNA by various chemical oxidants. To elucidate its biochemical and biophysical effects on RNA replication, the site-specifically modified oligoribonucleotides containing 5-OHU were synthesized with C5-hydroxy-5'-ODMTr-2'-TBDMS-uridine phosphoramidite using automated solid phase synthesis. The base-pairing properties of nucleotides opposite 5-OHU in 24 mer oligoribonulcleotides with dNTP were studied using three reverse transcriptases (Super-$Script^{TM}II$-, AMV-, MMLV-RT) in cDNA synthesis. Adenine as well as guanine was incorporated preferentially by all reverse transcriptases. In the UV-melting temperature experiment, the results from the relative stabilities of the base pairs were A : 5-OHU > G : 5-OHU > T : 5-OHU $\approx$ C : 5-OHU. Circular Dichroism (CD) studies showed that DNA-RNA containing 5- OHU heteroduplexes exhibit a similar conformation between the A-type RNA and B-type DNA. These results suggest that 5- OHU from oxidative damage was mainly influenced by adenine mismatch.

• 한국환경보건학회지
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• 제24권2호
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• pp.126-133
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• 1998

Effects of B(a)P on preimplantation mouse embryos in vitro were studied. Preimplantation mouse embryos were exposed to a concentration of 0.3, 1, 3 and 10 $\mu$M B(a)P for 72 hrs. The toxicological effects of B(a)P were evaluated by morphological observation of embryos up to the blastocyst stage, and by measuring DNA, RNA and protein synthesis by radioactive precursor incorporation. At 1 $\mu$M B(a)P did not affect preimplantation development but interfered with hatching and ICM formation. Suppressing effect of ICM formation was dose dependent. At the eight cell stage, the developmental rate was decreased at above 3 $\mu$M of B(a)P. At the blastocyst stage, attachment and trophoblast outgrowth were diminished at the 10 $\mu$M of B(a)P and ICM formation was decreased at 1 $\mu$M of B(a)P. Inner cell number of blastocyst was decreased dose dependently. So, number of ICM was one of the most sensitive and toxicological end point. The RNA incorporation rate of 0.1 $\mu ^3$H-uridine was dosedependent and the protein incroporation of 0.5 $\mu Ci ^{35}$S-methionine showed a significant decrease after 48 hrs. But the DNA incorporation rate of methyl-$^3$H thymidine was not affected. Our results suggested that B(a)P did not affect the DNA replication but transcription was inhibited by dose dependent manner. There delay of development during the blastocyst stage was mainly due to the inhibition of RNA synthesis followed by protein synthesis.

• 동의생리병리학회지
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• 제19권3호
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• pp.623-627
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• 2005

Abnormal thyroid cell proliferation has a very important role in hypothyroidism. Thyroid stimulating hormone (TSH) stimulates proliferation and maintains differentiated function in thyroid follicular cells. A functioning rat thyroid cell line (FRTL) was used to study the effect of Gamgung-tang (GGT, Glycyrrhizae Radix, black beans, Angelicae Radix and Cnidii Rhizoma) on proliferation and cAMP accumulation of thyrocytes. Proliferation of cell was assessed by DNA synthesis and incorporation of $[^3H]thymidine$ into DNA. The concentration of cAMP was measured simultaneously with growth assessment. Extract of GGT ($0.15{\sim}0.9\;mg/ml$ increased DNA synthesis in a dose-dependent manner. GGT at 0.6 (p<0.05) and 0.9 mg/ml (p<0.01) significantly increased $[^3H]thymidine$ incorporation. A comparable effect was observed with TSH. GGT also enhanced cAMP accumulation. These results indicate that GGT increases the proliferation of thyrocytes and may be considered a promising agent for the treatment of autoimmune thyroid disease.

• 생약학회지
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• 제34권3호통권134호
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• pp.237-241
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• 2003

본 연구는 참깨 종자로부터 추출, 분리된 세사몰린의 백혈병 HL-60 세포의 생장억제에 미치는 영향을 조사하였다. 세사몰린은 농도와 시간 의존적으로 HL-60 세포의 생합성을 억제하였다. $60{\sim}100\;{\mu}g/ml$ 농도의 세사몰린 범위에서 사포증식이 억제적이었다. $200\;{\mu}g/ml$ 이상의 세사몰린 농도에서 HL-60 세포에 세포파괴성으로 나타났다. 그리고 $60\;{\mu}g/ml$에서 HL-60 세포의 DNA, RNA, 단백질의 합성억제 정도는 35.1%, 6.1% 5.3%였다. 반면에 $200\;{\mu}g/ml$에서의 억제 정도는 각각 86.8%, 81.5%, 96.7%였다. DNA 합성에 대한 세사몰린의 억제효과는 비가역적이었다.