• Korean Journal of Microbiology
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• v.26 no.3
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• pp.162-166
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• 1988

Bacteriophage M13 DNAs carrying the wild type or base substituted SV40 DNA replication origins were used for replication assay. In vivo and in vitro assay with African green monkey cell line COS-1 showed that the replication of M13-SV40 recombinant DNAs was restricted like a pBR322 SV40 recombinant DNA(Lusky and Botchan, 1981). Furthermore, recombinant phage DNAs isolated from the transfected siminan cells subsequently show a reduced ability to retransform E. coli. But pATSV-W(Kim et al., 1988) was replicated in COS-1 cells normally. We think that a poison sequence may exist on bacteriophage M13 DNA like pBR322.

• YAKHAK HOEJI
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• v.43 no.5
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• pp.623-628
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• 1999

DA-125, a new antitumor agent, was compared with adriamycin, a known DNA intercalator, in terms of inhibitory mechanism of DNA replication by using replicating simian virus 40 (SV40) genome in vivo. In analyzing the SV40 DNA replication intermediates present in cells treated with DA-125, it was not observed to accumulate B-dimers of SV40 DNA which are prominent in adriamycin-treated cells. However, treatment with DA-125 induced dose-dependent formation of DNA-topoisomerase complex which is characteristic of topoisomerase poisons. In addition, DA-125 showed more efficient in inhibiting SV40 DNA replication than adriamycin. Therefore, on the basis of this observation, we suggest that DA-125, a derivative of adriamycin, inhibits DNA replication by blocking topoisomerase activity as a toposomerase poison although adriamycin blocks topoisomerase activity as a DNA intercalator.

• The Korean Journal of Zoology
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• v.28 no.3
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• pp.166-178
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• 1985

In order to express hepatitis B surface antigen $(HB_sAg)$ containing pre-surface antigen region in mammalian calls, 2.7 kb DNA fragment containing pre-surface region-$HB_sAg$ gene poly(A) addition site of HBV genome was cloned into simian virus 40(SV 40) based chimeric vector pSVOB. 2.7 kb DNA fragment was derived from pHBVD 107 containing tandem copies of the HBV genome in a head-to-tail arrangement by Bgl II digestion. Construction of the vector pSVOE involved the incorporation of SV40 sequences spanning the viral origin of replication and 72 bp repeats (enhancer) into a pBR 322 derivative lacking sequences which inhibit replication in mammalian cells. Bam HI linker was inserted at the Pvu II site in the proximity of SV40 late promoter of pSVOE and named as pSVOB. To construct the recombinant plasmid pSVBS, pHBVD 107 was digested with Bgl II to isolate 2.7kb DNA fragment and the fragment was ligated into the Bam HI site of pSVOB by ligation. Preliminary result showed that the recombinant plasmid pSVBS produced $HB_sAg$ in the monkey cell producing large T antigen (COS cell).

• Journal of Life Science
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• v.11 no.4
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• pp.371-378
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• 2001

The effects of the RM 60 series on DNA replication systems were examined by using simian virus 40 (SV40) DNA replication system in vitro. The RM 60 series inhibited the DNA replication in the initiation step rather than in the elongation step. Polymerase$\alpha$-primase activity and toposiomerase I activity study were performed subsequently, the RM 60 seies increased the polymerase $\alpha$-primase activity in a low dose, but decreased the activity in a higher dose. The topoisomerase I activity was inhibited by the RM 60 series. This result suggests that the RM 60 series might inhibit some molecules which are required to establish replication forks during the initiation step of the DNA replication.

• Journal of the Korean Chemical Society
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• v.46 no.2
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• pp.151-156
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• 2002

Fucoidan is a kind of polysaccharides in brown seaweeds. For the past years have been extensively studied due to their numerous biological activities : anticancer, anticoagulant, antithrombotic, anti-inflammatory and antiviral. In this study, we h ave extracted fucoidan from the Korean brown seaweeds and examined it's anticancer activities for employed SV40 DNA replication assay, RPA-ssDNA binding assay of replication protein A(RPA: known as human single-stranded DNA-binding protein essential for DNA rep-lication) and MCF7 cell growth inhibition assay. In addition to, we found that chemically sulfated fucoidan'santicancer activity is more higher than natural and desulfated fucoidan. It seem that fucoidan's sulfate group affect on DNA replication, cause of decrease RPA's DNA binding activity. These results suggests that sulfated fucoidan from Korean brown seaweeds have anticancer activity.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.218-225
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• 1999

We isolated the ANRI fragment from Aspergillus nidulons that could autononlously replicate and enhance transformation efficiency about $10^4$ fold compared lo the integrative vector in Saccha,omgcer cerevisioe. In A. nidulans recombinant plasmid pLJ16-4.5 which carries the 4.5 kb EcoRI fragment of ANRI showed a 170-[old increase of transformation efficiency compared to the integrative vector pLJ16 and could be recovered from iransfonnants as an intact form. Estimated copy number of transforming plasmid pLJ16-4.5 was scored as 2 to 3 copies in transformed A. nidulans. Recoinbinant plasinid pILJ16-4.5 is inilotically unstable; being lost Irom 65% of aswual progeny of transformants on selective medium and 90% on complete medium. Southern analysis of transformant DNA showed that the pILJ16-4.5 is maintained in free form. The sequencing data showed that ANRl fragment was originated from mitochondiral DNA of A. nid~ilans and contained high AT content as much as 74.7%. One ARS consensus sequence (A/T)TTr4T(A/G)TTT(AiT). I I ARS-like sequence (agreement 10 of 11) and ABFl binding core consensus sequence (TCN7ACG). Also six gyrase binding core consensus sequence (YRTGNYNNY: y=C or T, R=A or G, N=A, G, C or T) of $\Phi$X174 and SV40 DNA and one b site (CACTTTACC) combining with gyrase in ColEl are shown. ANRl can be developed as a repl&ng plasinid for lransfoimation system in A. nirlulmis.