• 미생물학회지
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• 제27권1호
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• pp.16-20
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• 1989

The effect of E. coli plasmid DNA sequences contained by chimeric vectors on plasmid replication was investigated. We constructed YRp7- or 2.$\mu$m circle-based plasmids containing E. coli plasmid DNA sequences and those not containing it. By examining their maintenance in yeast, we showed that plasmid without E. coli plasmid DNA sdquences was nore stable and presented higher copy number, and espressed higher level of hepatitis B viral surface antigen as a foreign gene. This result suggested that E. coli plasmid DNA sequences within chimeric plasmid somehow inhibited plasmid replication in yeast.

• KSBB Journal
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• 제15권1호
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• pp.84-87
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• 2000

포항 선형 가속기로부터 얻은 ultrasoft X-선이 대장균의 돌연변이 유도와 plasmid DNA 변이에 주는 영향을 알아보았다. 빔을 조사함에 따라 supercoil 형태의 plasmid DNA가 relaxed 형태로 변하고, 그후 선형으로 변해 감을 확인하였다. 빔을 조사한 plasmid DNA를 E. coli에 형질전환하여 $\beta$-galactosidase의 돌연변이 균을 분리하였고, 빔을 직접 조한 E. coli균으로부터도 $\beta$-galactosidase의 돌연변이 균을 얻었다. 변이된 plasmid DNA와 변이 대장균들의 plasmid DNA의 염기 부분을 변화를 확인하였으며 이 빔에 의해 주로 변이가 일어나는 부분이 있음을 알았다.

• Journal of Radiation Protection and Research
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• 제31권2호
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• pp.65-68
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• 2006

본 연구에서는 boron 화합물인 BSH(Boron Sulfhydryl Hydride)의 농도와 중성자 및 감마선 방사선 조사선량에 따른 plasmid DNA의 손상 정도를 관찰하였다. Plasmid는 pBR 322(2870 bp)와 ${\Phi}X174$ RF DNA(5386 bp)를 사용하였고 조사 후 DNA의 손상 정도는 agarose gel 전기영동 상에서 관찰하였다. 중성자 조사에서는 plasmid DNA의 손상 정도는 BSH의 농도 및 조사 선량이 증가함에 따라 증가하였으나 감마선 조사에서는 조사하지 않은 대조군과 큰 차이를 나타내지 않았다. Plasmid DNA의 손상 양상은 BSH 존재시 중성자 및 감마선 조사에서 다소 다름을 알 수 있었다.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1160-1165
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• 1998

When total cellular DNA was isolated from Porphyra tenera by ultracentrifugation on Hoechst dye/CsCl gradients method, plasmid like DNA's were concentrated at the upper band which were characterized with a A＋T rich organelle DNA's in the CsCl gradients. Based on their electrophoretic migration in different concentration of agarose gel, buffer system, and electric power etc. and the results of restriction digestion, the plasmid like DNA's were concluded to have circular conformation. This is the first report of putative circular plasmid DNA from the P. tenera, which is a autonomously replicating plasmid existing with a high copy number plasmid in the cell. The minimum size of this plasmid estimated by restriction endonuclease digestion was appeared to be 2.5kb in size.

• Archives of Pharmacal Research
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• 제27권12호
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• pp.1263-1269
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• 2004

The objective of this study was to characterize immunoliposomes carrying plasmid DNA with optimal encapsulation efficiency and antibody density. Plasmid DNA was encapsulated by the freezing/thawing method into liposomes composed of POPC (1-palmitoyl-2-oleoyl-sn-glycerol- 3-phosphocholine), DDAB (didodecyl dimethyl ammonium bromide), DSPE-PEG 2000 (distearoyl phosphatidyl ethanolamine polyethylene glycol 2000) and DSPE-PEG 2000-maleimide. The liposomes carrying plasmid DNA were extruded through two stacked polycarbonate filters, of different pore size, to control the liposome size. Then, rat IgG molecules were conjugated to the liposomes. The immunoliposomes containing plasmid DNA were separated from the free plasmid DNA and unconjugated IgG by Sepharose CL-4B column chromatography. The DNA amount encapsulated was affected by DDAB (cationic lipid) concentration, the initial amount of plasmid DNA between 10 ${\mu}g$ and 200 ${\mu}g$, the total lipid amount and plasmid DNA size, but not significantly by liposome size. By varying the ratio of DSPE-PEG 2000-maleimide to IgG, the number of IgG molecules per liposome was changed significantly.

• 미생물학회지
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• 제24권2호
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• pp.106-112
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• 1986

자연계에서 분리한 Pseudomonas에서 크기가 매우 큰 plasmid (약 180 megadaltons:를 분리하였다. 이 plasmid는 기존의 plasmid 검출방법보다 더 온화한 조건에서 분리되었다. Alkalin., sodium dodecyl sulfate (pH 12. 45)를 사용하여 chromosomal DNA를 변성시킨 뒤 $55^{\circ}C$로 열처리 하여 covalently closed circular DNA 의 손실을 최대한으로 방지하였고, polyethylene glycol을 최종농도 10%로 첨가하여 plasmid DNA를 선택적으로 농축하였다. 한편, 이 plasmid는 mitomycin C를 처리하여 얻은 cured sitrains에서는 나타나지 않아 salicylate를 분해하는 새로운 plasmid로 확인되었다.

• 한국미생물·생명공학회지
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• 제11권3호
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• pp.163-168
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• 1983

Pnicillinase를 분필하는 Streptomyces bobili YS-40균주의 plasmid DNA를 phemol방법으로 유출하여 Bocillus subtilis IAM 12118균주에 형질 전환시켜서 penicillin 내성 plasmid DNA가 표현되게 하였다. 형질전환에 미치는 최적 pH와 온도는 각각 7.0, 3$0^{\circ}C$으로 나타났다. DNA와 Competent cell을 20분 이상 접촉시킴으로서 형질전환이 잘 일어났으며 DNA의 농도가 증가할수록 transformant의 수도 증가했다. DNA inhibitor 로 사용되는 lysine 의 첨가로 형질전환의 빈도가 약 6배정도 상승되었으며 chloramphenicol은 형질전환의 빈도에 별 영향을 미치지 않았다.

• 농업과학연구
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• 제41권4호
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• pp.351-359
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• 2014

For identifying the plasmid DNA coding cry gene of Bacillus thuringiensis subsp. aizawai KB098 with high insecticidal activity against Spodoptera exigua, mutant isolates with no crystal protein were produced by $42^{\circ}C$ incubation condition and then mutant plasmid DNA band patterns were compared with those of KB098. KB098 isolates had 4 cry genes, cry1Aa, cry1Ab, cry1C, cry1D, and also had been found seven plasmid DNA. Though the SDS-PAGE experiment, it was confirmed that mutant didn't produce 130~145kDa protein band involved in bipyramidal shape crystal. Also, five mutant isolates had no cry genes coding plasmid DNA in PCR. In result of comparison the plasmid DNA of KB098 and 5 mutant isolates, only 1 plasmid DNA band was left out in mutant plasmid DNA pattern, so that the missing band was extracted from the gel. The missing(disappeared) plasmid DNA was the largest molecular size among the 7 plasmid DNA of KB098 and it was also confirmed this plasmid DNA had all 4 cry genes through PCR.

• 미생물학회지
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• 제37권2호
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• pp.120-123
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• 2001

Sphingomonas chungbukensis DJ77에서 난분해성 물질 분해 유전자가 chromosome 또는 plasmid 존재하는지를 규명하였다. 야생주 DJ77의 plasmid를 mitomycin C를 이용하여 curing 시킨 후, 각각 phenanthrene과 biphenyl이 단일 탄소원으로 첨가된 최소배지에서 배양한 결과 야생주는 성장을 하지만 plasmid가 제거된 DJ77은 성장하지 않았다. 각각의 plasmid DNA를 분리한 수 이미 클로닝된 방향족 탄화수소 분해에 관련된 DNA를 probe로 하여 Southern hybridization을 한 결과 야생주에서만 positive signal을 발견할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제26권4호
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• pp.291-297
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• 1996

Liposomes of $pSV-{\beta}-Galactosidase$ vector plasmid DNA with various lipid composition were prepared by the thin-film method. Size distribution, shape and the efficiency of plasmid DNA encapsulation were investigated. Effect of sonication time on the plasmid DNA entrapment in liposomes and stability at $4^{\circ}C$ were also examined. Sizes of neutral liposomes were about 100-200 nm and above $1\;{mu}m$, and those of cationic liposomes were about 400-600 nm and above $1\;{mu}m$. Shapes of liposomes entrapped plasmid DNA were spherical. Proper sonication time for better entrapment was below 15 minutes and stability at $4^{\circ}C$ was decreased rapidly after 1 day. Plasmid DNA entrapments of complex liposomes of various lipids were higher than those of liposomes made from one sort of lipid. Plasmid DNA entrapments of cationic liposomes were higher than those of neutral liposomes.