• 제목/요약/키워드: RNase H

검색결과 47건 처리시간 0.03초

잠란(蠶卵)의 초기발육과정(初期發育過程)에 따르는 RNase활성(活性) 및 핵산량(核酸量)의 변동(變動) 및 그 X선조사(線照射)에 의한 영향(影響)에 관(關)한 연구(硏究) (Variation of RNase activities and nucleic acid content of non-irradiated and irradiated eggs of Bombyx mori during early development of embryo)

  • 이기영;전형원
    • Applied Biological Chemistry
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    • 제15권2호
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    • pp.163-168
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    • 1972
  • Previously identified female pupae were X-irradiated with a dose of 1000r one day prior to moth transformation. Female mothes from irradiated and non-irradiated pupae were copulated with normal male ones and allowed to lay eggs. Fertilized eggs were collected at 6 intervals such as 5, 15, 45, 90 minutes, 12 and 40 hours after laying, and deep-freezed immediately after each collection until measurements. RNase activity and nucleic acid content were determined with each sample and following results were obtained. 1) It was proved to exist two RNases in silk worm eggs as in mammalian tissues, one active maximally at pH 5.8 and the other at pH 8.0, and the acid RNase activity was much higher than that of alkaline RNase. 2) The activity of acid and alkaline RNases increased remarkably during early development of the embryo of silk worm eggs, reaching the maximum activity at 45 minutes from laying time in non-irradiated group. There was no appreciable difference in two RNase activities for 45 minutes after laying in both control and irradiated groups, but the activity of acid and alkaline RNases in latter group was three times as much as that in former group, at 90 minutes from laying time and it was also found the acid RNase activity was 1.8 times higher than alkaline one in irradiated group. 3) The RNA-P content of control group increased considerably for initial 45 minutes, followed by a decline 45 minutes later with sight but steady increase thereafter. The RNA-P content of irradiated group, however, increased at initial 5 minutes, followed by a marked fall 90 minutes after laying, with no change thereafter. The DNA-P of control group showed a sharp increase for initial 45 minutes, followed by a decline 45 minutes later with no appreciable change thereafter, whereas that of irradiated group showed an increase at initial 15 minutes, followed by a sharp decline for following 45 minutes with a gradual increase thereafter. It was thus proved that the synthesis of nucleic acid in silk worm eggs was much suppressed by X-irradiation during early development of embryo. 4) The RNase activity varied in parallel with the RNA-P content in control group, but the RNA-P content in irradiated group was shown to be minimum value in concidence with the maximum activity of both RNases.

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Indole acetic acid 와 Abscisic acid 가 핵산(核酸)과 RNase 에 미치는 영향에 관(關)하여 (The Effect of Indole Acetic and Abscisic Acid on Ribonucleic Acid and Ribonuclease)

  • 조도현;이춘영
    • Applied Biological Chemistry
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    • 제15권3호
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    • pp.181-186
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    • 1972
  • 소맥 자엽초를 일정한 길이로 절단하여 식물생장 조질제인 교dole acetic acid (IAA)와 abscieic acid (ABA)를 처리하여 아래와 같은 결과를 얻었다. 1. IAA는 고분자 핵산의 F2와 F3을 감소시킨 반면에 ABA는 F4를 증가 시켰다. 2. IAA는 G2 isozyme의 활성도를 증가시켰으나 G3 isogyme의 활성도는 ABA에 의하여 감소되었다. 3. 상기의 결과로 부터 IAA와 ABA는 핵산과 RNase에 대하여 어느정도 공통되는 효과를 갖는다는 것이 암시됨을 알수 있었다. 4. SH group을 저해하는 pb, p-hydroxymercury benfoa 둥에 의해서 발현되는 latent RNase의 활성도는 나타나지 않았다.

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Improved Detection of Viable Escherichia coli O157:H7 in Milk by Using Reverse Transcriptase-PCR

  • Choi, Suk-Ho;Lee, Seung-Bae
    • 한국축산식품학회지
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    • 제31권2호
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    • pp.158-165
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    • 2011
  • A sensitive reverse transcriptase-PCR (RT-PCR) method to detect viable Escherichia coli O157:H7 in milk was established. The primer sets were designed based on the nucleotide sequences of the rfbE (per) and wbdN genes in the O157 antigen gene cluster of E. coli O157:H7. RT-PCR using five different primer sets yielded DNA with sizes of 655, 518, 450, and 149-bp, respectively. All five of the E. coli O157:H7 strains were detected by RT-PCR, but 11 other bacterial species were not. The sensitivity of RT-PCR was improved by adding yeast tRNA as a carrier to the crude RNA extract. The RT-PCR amplifying the 149-bp DNA fragment was the most sensitive for detecting E. coli O157:H7 and the most refractory to the bactericidal treatments. Heat treatment at $65^{\circ}C$ for 30 min was the least inhibitory of all bactericidal treatments. Treatment with RNase A strongly inhibited the RT-PCR of heated milk but not unheated milk. This study described RT-PCR methods that are specific and sensitive with a detection limit of 10 E. coli O157:H7 cells, and showed that pre-treating milk samples with RNase A improved the specificity to detect viable bacteria by RT-PCR.

RNase Resistant RNA in the Egg of Xenopus laevis: I. RNA Extraction and in Vitro Labeling

  • Chung, Hae-Moon
    • 한국동물학회지
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    • 제20권1호
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    • pp.9-18
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    • 1977
  • RNA 분해효소에 저항하는 RNA 분자들이 양서류의 난에 존재하는지의 여부를 조사하기 전에 필요한 몇가지 예비실험을 하기 위하여 Xenopus laevis에 난에서 RNA를 추출 하였다. Sephadex G-100 column chromatography는 세 개의 peak을 항상 보여주고 있다. 첫째 peak에 포함되어있는 고분자량의 RNA만을 $^{3}H$-dimethyl sulfate를 사용하여 시험관내에서 label하여 tRNA로부터의 base paired oligonucleotide의 참여를 배제하였다. 이 방법으로 아주 높은 specific activity를 얻을 수 있었으며 또한 부착된 methyl group은 대단히 안정성을 보였다.

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Characterization of Echinostoma cinetorchis endoribonuclease, RNase H

  • Lim, Sung-Bin;Cha, Seok Ho;Jegal, Seung;Jun, Hojong;Park, Seo Hye;Jeon, Bo-Young;Pak, Jhang Ho;Bakh, Young Yil;Kim, Tong-Soo;Lee, Hyeong-Woo
    • Parasites, Hosts and Diseases
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    • 제55권4호
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    • pp.451-455
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    • 2017
  • Echinostoma cinetorchis is an oriental intestinal fluke causing significant pathological damage to the small intestine. The aim of this study was to determine a full-length cDNA sequence of E. cinetorchis endoribonuclease (RNase H; EcRNH) and to elucidate its molecular biological characters. EcRNH consisted of 308 amino acids and showed low similarity to endoribonucleases of other parasites (<40%). EcRNH had an active site centered on a putative DDEED motif instead of DEDD conserved in other species. A recombinant EcRNH produced as a soluble form in Escherichia coli showed enzymatic activity to cleave the 3'-O-P bond of RNA in a DNA-RNA duplex, producing 3'-hydroxyl and 5'-phosphate. These findings may contribute to develop antisense oligonucleotides which could damage echinostomes and other flukes.

Analysis of Transcripts Expressed from the UL47 Gene of Human Cytomegalovirus

  • Hyun, Jong-Jun;Park, Hyo-Soon;Kim, Ki-Ho;Kim, Hung-Jin
    • Archives of Pharmacal Research
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    • 제22권6호
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    • pp.542-548
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    • 1999
  • The UL47 gene (b 60390-b 60388) located in the unique long region of the human cytomegalovirus (HCMV) AD169 strain genome was analyzed RNA mapping. Northern blot analysis showed that the UL47 gene was expressed at late times after infection (72 h postinfection). The 9.7-kb transcript was expressed in the infected cells but not in phosphonoformate-treated cells at 72 hpi, indicating that the UL47 gene was only expressed at late times after infection. To map the 5'-end and 3'-end of UL47 transcripts, primer at late times after infection. To map the 5'-end and 3'-end of UL47 transcripts, primer extension and RNase protection analysis were performed. Primer extension analysis revealed that the transcription initiation site of UL47 was located in 27 bp downstream (b 60323) of the TATA box motif. The sizes of UL47 ORF (approximately 2.9-kb) and UL48 ORF (approximately 6.7-kb) deduced from computer sequence analysis suggest that the expressed 9.7-kb transcript of UL47 uses the 3'-end polyadenylation signal of Ul48. The result of RNase protection determined that the 3'-end of UL47 RNA utilized the 3'-end polyadenylation signal of UL48, which is located in HCMV genome b 70082.

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Complementary DNA Cloning of Genomic RNA in Orchid Strain of Tobacco Mosaic Virus

  • Won Mok Park
    • Journal of Plant Biology
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    • 제37권3호
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    • pp.349-355
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    • 1994
  • Viral RNA was extracted from a purified orchid strain of tobacco mosaic virus (TMV-O) from Cymbidium "Grace Kelly". Polyadenylated viral RNAs were primed with Not I-oligo (dT) primer-adapter. First-strand cDNAs were reversely transcribed by Moloney murine leukaemia virus reverse transcriptase (RNAse H-), and then second-strand cDNAs were synthesized by RNase H and DNA polymerase I. The resulting double-stranded cDNAs were ligated into pSPORT1 vector and transformed into competent E. coli strain JM109 cells. The size of cDNAs within the recombinant plasmids was ranging from 0.9 to 3.9 kb. Among the selected clones, pTMO-0205 and -0210 covered the 3' half and the 5' half of the viral genomic RNA, respectively, which were covering more than 99% of the viral genemo size based on sequencing analysis. Two cDNA fragments which were 3.1 kb BamHI and NotI fragement released from pTMO-0.205 and 3.3 kb SalI and BamHI fragment released from pTMO-0210 were ligated with T4 DNA ligase. The clone was almost entire length, lacking only 31 nucleotides from the 5' terminus based on the sequencing result. This method was shown to be efficiently applicable to other plant viral gnomic RNA for the construction of cDNA.n of cDNA.

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