• BMB Reports
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• 제28권2호
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• pp.143-148
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• 1995

In E. coli, chromosomal DNA associated with proteins is condensed into an organized structure known as nucleoid. Using a nitrocellulose filter binding assay to identify proteins forming nucleoid, a 21 kDa protein was purified from E. coli. The molecular weight of the purified protein was 21 kDa on SDS-polyactylamide gel electrophoresis and 24 kDa on gel permeation chromatography. A molecular weight of 21 kDa on SDS-polyacrylamide gel electrophoresis is unique among known proteins which are believed to be involved in the formation of nucleoid in E. coli. The 21 kDa protein nonspecifically binds to both double-stranded and single-stranded DNA. Sedimentation in a sucrose gradient revealed that the protein induced significant condensation of both supercoiled plasmid DNA and linear bacteriophage $\lambda$ DNA On the basis of quantitative Western-blot analysis, approximately 40,000 molecules of the protein were estimated to exist in an E. coli. The biochemical properties and cellular abundance of the 21 kDa protein suggest that this protein participates in the formation of nucleoid in E. coli.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.254-254
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• 2006

The sensitivity of plasmid DNA (pDNA) to S1 nuclease, an enzyme to cleave a single-strand DNA, was dramatically modulated through a supramolecular assembly (polyion complex micelle) with a synthetic block copolymer, poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL). The pDNA condensed in stoichiometric charge ratio was cleaved into 7 fragments each being 10/12, 9/12, 8/12, 6/12, 4/12, 3/12, and 2/12 of the original DNA length, on the other hand, the pDNA condensed in higher charge ratios (>4), were digested into non-specific manner. Condensation of the pDNA was investigated from two viewpoints that how does the rigid DNA molecules fold and condense and how does the condensation influence their biological activity.

• Macromolecular Research
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• 제12권5호
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• pp.501-506
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• 2004

We have investigated the spectral properties of DNA, including its electric absorption, circular and linear dichroism (CD and LD), and fluorescence emission, in the DNA-linear polyethyleneimine (LPEI) and DNA-branched polyethyleneimine (BPEI) complexes at various polymer concentrations. The spectral properties of both complexes are similar. We observed a relatively moderate change in the absorption and CD spectra at low amine/DNA phosphate (NIP) ratios (< 0.5), followed by a drastic collapse within the N/P range from 0.8 and 1.0. The absorption and CD spectra recovered as the N/P ratio increased to ca. 1.2. In contrast, the LD and emission of ethidium intercalated between the DNA bases decreased almost linearly at N/P ratios between 0.0 and 1.0. These spectra never recovered at higher N/P ratios. We believe that the moderate changes in the spectrum at low N/P ratios occurred because of electrostatic interactions between DNA and BPEI, while the collapsed spectra at N/P ratios between 0.5 and 1.5 occurred because of condensation/aggregation of the DNA. Considering the structure of the polymers, we suggest that the secondary amino group of LPEI and all three amino groups of BPEI are equally involved in DNA condensation.

• 미생물학회지
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• 제38권3호
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• pp.213-220
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• 2002

일본뇌염바이러스(Japanese encephalitis virus, JEV)의 구조단백질 capsid (C), precursor membrane (prM/M), 및 envelop (E) 단백질의 독립적인 발현을 위한 inducible expression system을 구축하였다. 발현세포주로는 BHK-21을 사용하였으며 발현의 induction에는 tetracycline analog인 doxycycline이 사용되었다. Transfectant BHK-21/IV(vector대조구), BHK21/IC(C), BHK-21/IP (prM/M),및 BHK-21/IE는 G418과 hygromycin 존재하에 클로닝되었으며 doxycycline induction에 따른 각 유전자의 mRNA 전사를 확인하였다. 세포의 성장곡선, chromatin condensation, internucleosomal DNA fragmentation, 및 flow cytometry에 의한 DNA content profile 분석을 통해 induction에 의한 각 구조단백질의 발현이 숙주세포에 미치는 영향을 조사하였다. 세 transfectants 모두 세포성장이 감소하고 chromatin이 응축되었다. 그러나 DNA fragmentation 및 DNA content profile 분석에서는BHK-21/IC만이 induction에 따라 상응하여 반응하였다. 이상의 결과는 JEV 감염에 의한 apoptotic 세포사멸 유도기전에서 capsid 단백질이 직접적이고 독립적인 영향요인이 될 수 있음을 제시한다.

• Clinical and Experimental Reproductive Medicine
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• 제40권1호
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• pp.23-28
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• 2013

Objective: The aim of the present study was to examine the relationship among male age, strict morphology, and sperm chromatin structure and condensation. Methods: Sperm samples from a total of 100 men underwent semen analysis, and sperm chromatin structure and condensation were assessed with toluidine blue (TB) and aniline blue (AB) tests. Results: Prevalence of strict morphology of less than 4%, and abnormal sperm chromatin structure and condensation did not show any statistically significant differences according to male age (p=0.605, p=0.235, and p=0.080). No significant correlation was demonstrated among age of male partners, strict morphology, and abnormal sperm chromatin structure using TB and AB tests. However, abnormal sperm chromatin condensation was positively associated with sperm chromatin structure (r=0.594, p=0.000) and showed negative correlation with strict morphology (r=-0.219, p=0.029). Conclusion: The tests for sperm chromatin condensation showed a significant association with strict morphology. Further study is needed to elucidate the relationship between clinical outcome and sperm chromatin tests.

• 생명과학회지
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• 제12권4호
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• pp.469-476
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• 2002

남미지역에 서식하는 Tabebuia avellanedae의 수피에서 동정된 천연 quinone계 물질인 $\beta$-lapachone은 DNA topoisomerase I 억제제 이외 다양한 약리학적 기능이 있을 것으로 추정되지만 그 기능이 명확하지 않다. $\beta$-lapachone의 생리활성 기전 해석의 일환으로 본 연구에서는 인체 전립선 DU-145 암세포주의 성장에 미치는 $\beta$-lapachone의 영향을 조사하였다. p-lapachone이 함유된 배지에서 자란 암세포들은 $\beta$-lapachone 처리 농도 의존적으로 성장이 억제되었으며, 이는 apoptosis가 유발된 세포에서 특징적으로 관찰되는 chromatin condensation 및 DNA fragmentation 현상을 유발하였고, DNA flow cytometry 분석결과 apoptotic-sub Gl기에 해당하는 세포들의 빈도도 증가되었다. 또한 poly (ADP-ribose) polymerase 및 $\beta$-catenin 단백질의 발현에서도 apoptosis 유발 특이적인 분해 현상을 보여주었으며, DU-145 전립선 암세포에서 $\beta$-lapachone에 의한 이러한 apoptosis의 유발에는 Bax의 발현증가에 따른 Bcl-2 발현의 감소가 중요한 역할을 할 고 있는 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제11권2호
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• pp.151-156
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• 2003

Cornis fructus have various biological effects and major chemical components have been tannins, saponins, ursolic acids, gallic acids, linoleic acids, morronisides, cornins and loganins. The main aim of the present study is measurment the effect of chloroform extract from Cornis fructus on proliferation inhibition and Cell death. Cells were cultured in the presence of chloroform extracts from Cornis fructus for 48 h. after 48h treatment of B16/F10 melanoma cells with chloroform extracts, the cells were observed a dose-dependent inhibitions of cell viability with cell death in their proliferation. the cells were estimated cell viability, cell number, total DNA fragmentation and chromatin condensation in a dose-dependent manner. It also caused cell death as measured by cell morphology, DNA fragmentation and nucleus chromatin condensation. therefore, these results suggest that chloroform extracts from C. fructus is inhibitory proliferation and is related to cell death in this cells.

• Toxicological Research
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• 제20권1호
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• pp.63-69
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• 2004

Casapse-3 protease is known as a key role of apoptotic enzyme, and caspase-3 activity is a central event that occurs upstream of DNA fragmentation during apoptosis. This study demonstrates that chitosan pretreatment inhibits cadmium-induced apoptosis by attenuating the activity of caspase-3. We also analyzed the protective effect of chitosan on DNA fragmentation induced by cadmium. Cadmium toxicity was examined by DNA fragmentation and nuclear condensation with Hoechst stain. Caspase-3 activities were increased cadmium treated group for 3 hours compared with control. When chitosan (150 mg/ml) was pretreated at 30 min before cadmium treatment, cadmium cytotoxicity was suppressed in a dose-dependent manner evaluated by DNA fragmentation and caspase activity. From these results, it is suggest that the protective effect of chitosan pretreatment against cadmium-induced cytotoxicity is mediated through inhibition of caspase-3 protease activation and DNA fragmentation.

• 대한화학회지
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• 제29권5호
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• pp.533-538
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• 1985

Spermine에 의하여 誘發되는 凝縮 DNA 構造의 安定化에 있어서 hydrophobic interaction의 重要性을 試驗하기 위하여 spermine-DNA 複合體의 異例的 吸光度-溫度 樣相에 미치는 urea의 效果를 調査하였다. 그 結果 異例的 吸光度-溫度 樣相의 downward peak(trough) 領域에 이르는 相變移에 對한 cooperativity, enthalpy, midpoint의 값들이 Tm 領域의 값들 보다 urea에 敏感한 影響을 받았으며, urea의 濃度 增加에 따라 downward peak가 점차 사라졌다. 이 data는 異例的 吸光度-溫度 樣相을 構成하는 downward peak가 spermine에 의하여 誘發되는 hydrophobic interaction에 의한 凝縮된 tertiary structure의 形成을 나타내고 있다고 불 수 있다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.72.1-72
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• 2003

Generally, plants defend themselves against pathogens by structural and biochemical reactions. Defense structures act as physical barriers and inhibit the pathogen from gaining entrance and spreading through the plant. Xanthomonas axonopodis pv glycines, the causal pathogen of bacterial pustule of soybean, causes hypersensitive response (HR). When pepper fruits were inoculated with X. axonopodis pv. glycines, in situ, time-series defense-related structural changes occurred in the inoculated sites. Early responses were programmed cell death (PCD), characterized by condensation and vacuolization of the cytoplasm, condensation of nuclear materials, and fragmentation of the nuclear DNA, which were observed by transmission electron microscopy. Nuclear fragmentation was proven by TUNEL method under confocal laser scanning microscopy and DNA laddering through eletrophoresis. At later stages, plant responses were cell elongation and cell division, forming a periderm-like boundary layer that demarcated healthy tissues from the inoculation sites. Using several stains such as toluidine blue, sudan IV, annexin V, and phloroglucinol-HCl, defense-related materials and structural changes were also examined.