• 한국미생물·생명공학회지
• /
• 제49권3호
• /
• pp.316-319
• /
• 2021

Restriction endonucleases play an important role in molecular cloning, clinical diagnosis, and pharmacological drug studies. In this study, DNA-templated copper nanoclusters (DNA-CuNCs) were used to detect AluI endonuclease activity due to their high fluorescence emission and rapid synthesis of DNA-CuNCs under ambient conditions. Results showed that AluI activity was detected in a highly sensitive manner at low concentrations of AluI endonuclease by the fluorescence intensity of DNA-CuNCs. Additionally, its inhibition was monitored in the presence of daidzein under optimal conditions.

• Animal cells and systems
• /
• 제1권3호
• /
• pp.451-455
• /
• 1997

The effects of nalidixic acid, mitomycin C, and cadmium chloride $(CdCI_2)$ on the activity of 8-hydroxyguanine $(oh^8Gua)$ endonuclease, a DNA repair enzyme for oxidatively modified guanine, $(oh^8Gua$ were studied. Nalidixic acid and mitomycin C, typical inducers of the S0S DNA repair response in E. coli, showed different effects. Nalidixic acid raised the activity of this enzyme, but mitomycin C did not show such an effect. Cadmium chloride also induced the enzyme activity, These results show that the expression of $oh^8$ Gua endonuclease is regulated by multiple factors and can be induced under stressful conditions. In an attempt to demonstrate the importance of this enzyme in defense against DNA damage and mutagenesis, we also characterized mutM mutant for its oh8 Gua endonuclease activity. The mutM mutant showed no detectable $oh^8$ Gua endonuclease activity, unlike its wild type showing high activity. In addition, paraquat, a superoxide producing compound, failed to elevate $oh^8Gua$ endonuclease activity in this mutant. These results suggest that the mutM gene is identical to the $oh^8Gua$ endonuclease gene of E. coli. Taken together with previous reports, these results suggest that $oh^8Gua$ endonuclease plays a crucial role in the protection of aerobically growing organisms from threats of oxidative DNA damage and mutation.

• Journal of Photoscience
• /
• 제9권2호
• /
• pp.182-185
• /
• 2002

There are 3 UV DNA repair endonuclease activities in mammalian cells that cleave UV -irradiated DNA. Interestingly, mammalian UV endonuclease III with MW of 26.7kD has a lyase activity on AP sites. It also cleaves the phosphodiester bond within a cyclobutane pyrimidine dimer. Genomic analysis of human repair endonuclease III gene revealed that this gene has 100% sequence identity with ribosomal protein S3 (rpS3). Therefore, rpS3 seems to function both in translation and in DNA repair. This gene of about 6.1 kb contains 6 introns and 7 exons, and the first and fifth introns of human rpS3 gene contain functional U15 small nucleolar (sno) RNAs which appear to be involved in ribosome assembly. It is to be noted that the column profile of the endonuclease activity of rpS3 appears to be altered in Xeroderma Pigmentosum (XP) group D cells compared to normal cells indicating that this protein is involved in XP disease as well. XP is a human disease characterized by high sensitivity of skin by UV- or sun-light irradiation and by high frequency of developing skin cancers. We also report here that rpS3 protein is involved in other cellular functions.

• 한국미생물·생명공학회지
• /
• 제13권1호
• /
• pp.87-91
• /
• 1985

Hpa I endonuclease를 순수 정제하였다. 150g (wet weight)의 Haemophilus parainfluenzae로 부터 얻은 crude extract를 ammonium sulfate fractionation을 거친후 Heparin agarose, SP-sephadex, DEAE-sephadex, phosphocellulose 등 chromatography를 거쳐 최종적으로 0.2mg의 효소를 얻었다. Specific activity는 $2.2{\times}10^6units/mg$이었다. 얻어진 Hpa I endonuclease는 SDS-polyacrylamide gel에서 한개의 band를 보였고, 그 효소활성은 50mM NaCl과 pH 7.0과 7.5사이에서 가장 높았다.

• 한국광과학회:학술대회논문집
• /
• 한국광과학회 1997년도 학술대회지
• /
• pp.39-39
• /
• 1997

• BMB Reports
• /
• 제39권5호
• /
• pp.556-559
• /
• 2006

The Bcl-2 family of proteins regulates mitochondrial functions during cell death by modulating the efflux of death-promoting proteins such as cytochrome c and endonuclease G. Upon the binding of death ligands to their receptors, caspase-8 cleaves Bid, a BH3-only protein, into tBid that causes the mitochondrial damages resulting in the release of cytochrome c and endonuclease G. Also, another BH3-only protein, hNoxa, has been shown to induce the efflux of cytochrome c from the mitochondria. Whether the efflux proteins from the mitochondria in response to tBid or hNoxa are the same or different, however, has not been addressed. We have demonstrated that endonuclease G activities are not detectable among the proteins released from isolated mitochondria by hNoxa but are detectable in that by tBid. These results suggest that the efflux of proteins from the mitochondria are differentially modulated by tBid and hNoxa.

• Journal of Microbiology
• /
• 제38권2호
• /
• pp.88-92
• /
• 2000

A human ribosomal protein S3 (rpS3), which also functions as a DNA repair enzyme(UV endonuclease III), was expressed in a methylotrophic yeast, Pichia pastoris, and biochemically characterized. UV endonuclease activity was preiously characterized, and this activity of mammalian rpS3 was found to be non-specfic upon purification and storage. Under the Pichia expression system, the subcloned cDNA of the human rpS3 gene revealed a peptide of 42 kDa by SDS-PAGE and Western blot. The secreted form of human rpS3 rendered no endonuclease activity while the intracellular form showed UV specific endonuclease activity by the nick circle assay.

• 미생물학회지
• /
• 제25권1호
• /
• pp.73-79
• /
• 1987

A restriction endonuclease, Kpn I has been isolated from Klebsiella pneumonia. Cells were broken by sonication. After ultracentrifugation the supernatant containing Kpn I activity was further purified by Sepharose-6B gel filtration, DEAD-Cellulose, Heparin-Agarose, and Aminohexyl-Agarose column chromatography. Final enzyme preparation was essentially free of contamination exonuclease and phosphatase, as judged by ligation-recut test. Total activity of the enzyme recovered from 10 grams of cells was $4.7\times 10^5$ units.

• Biomolecules & Therapeutics
• /
• 제2권1호
• /
• pp.28-33
• /
• 1994

In order to obtain insight into the repair mechanism of DNA containing thymine photo-dimer, the conformation of the duplex d(GCGGTTGGCG).d(CGCCAACCGC) with a thymine dimer incorporated has been studied by proton NMR. NOE data show that, although the local environment around the thymine dimer is altered, the gross structural changes are relatively small. T$_4$endonuclease V exhibited a conformational change on complex formation with DNA. This conformational change occurred around histidine 16 which was close to tyrosine 129 located in the aromatic segment (WYKYY) near the C-terminus. It is likely that the interaction between T$_4$endonuclease V and DNA is strong since the complex was not dissociated up to 1.6 M NaCl.

• 미생물학회지
• /
• 제32권4호
• /
• pp.297-300
• /
• 1994

토양에서 분리한 방선균에서 제한효소 활성을 조사하여 그 가운데 Streptomyces diastatochromogenes로부터 제한효소 활성을 확인하였다. 이 균주의 제한효소 SdiI을 균체 15g으로부터 streptomycin sulfate침전, ammonium sulfate 침전, hydroxylapatite colume chromatography, Sephacryl S-200 HR column chromatography, hydroxylapatite column chromatography의 단계를 거쳐 분리하였고, SDS-polyacrylamide gel-electrophoresis에 의하면 소단위체 분자량은 약 35,000Da으로 추정되었다.