• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.86-89
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• 2006

The novel tetranuclear nickel (II) complex is a high rate accelerator in promoting hydrolysis of phosphate diesters. Nickel-bound bis-nitrophenyl phosphate (BNPP) can be $10^4$ times more reactive than the unbound BNPP. The large rate of enhancements by the complex slightly under basic condition has shown high catalytic activity in phosphate diester cleavage. The bell-shaped pH-rate profile indicated that the nickel-oxide form of the tetranuclear complex or its kinetic equivalent was the active species for cleaving BNPP. The catalytic hydrolysis between tetranuclear nickel (II) complex and phosphate diester proceeds via the formation of bidentate coordination of the anionic phosphate to the Ni (II) atom. This reveals that the complex has the possibility as artificial nuclease.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.96-105
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• 2002

A bacteriocin-producing strain identified as Pediococcus acidilactici was isolated from kimchi. The bacteriocin was identified to belong to the pediocin family and exhibited bactericidal activity against most Gram-positive bacteria as well as some Gram-negative bacteria. The bacteriocin was stable up to $80^{\circ}C with wide pH ranges (5.0-10.0). The bactericidal activity remained unchanged after treatment with nonproteolytic enzymes such as nuclease and ${\alpha}$-amylase, however, it was destroyed after treatment with protease. The bacteriocin was effectively extracted by the pH-mediated adsorption-desorption method and purified effectively by semi-preparative RP-HPLC. The molecular weight of the bacteriocin was 4,622, as determined by electrospray mass spectrometry. The amino acid sequence consisted of 44 amino acid residues with four cysteines. The high solubility and pH stability of the isolated pediocin provide definite advantages over nisin and other bacteriocins in regards to its potential applications.

• 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.

• BMB Reports
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• 제39권6호
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• pp.788-793
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• 2006

Bacterial DNA containing immunostimulatory CpG motifs can stimulate antigen-presenting cells to express co-stimulatory molecules and to produce various cytokines in vivo and in vitro. In this study, we fragmented macromolecular E.coli genomic DNA with DNase I, and analyzed the ability of the resulting DNA fragments to induce the NF-${\kappa}B$ activation and humoral immune response. Furthermore, using computational analysis and luciferase assay for synthetic ODNs based on the sequence of the immunostimulatory DNA fragments (DF-ODNs), an active component of DF-ODNs sequences was investigated. Experimental results demonstrated that DF-ODN is optimal for the NF-${\kappa}B$-responsive promoter activation in the mouse macrophage cell line and the humoral immune response in vivo. In agreement with the activity of the DF-ODNs processed by DNase I, a synthetic ODN based on the DF-ODN sequences is potent at inducing IL-12 mRNA expression in primary dendritic cells. These results suggest that the discovery and characterization of a highly active natural CpG-ODN may be achieved by the analyses of bacterial DNA fragments generated by a nuclease activity.

• Mycobiology
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• 제36권4호
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• pp.260-265
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• 2008

Cyclic voltammetric measurements were performed for Co(II), Ni(II), Cu(II) and Zn(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-succinic anhydride) (L) and Ni(II) and Cu(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-methacrylic acid) ($L^1$). The in vitro biological screening effects of the investigated compounds were tested against the fungal species including Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans and bacterial species including Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa by well diffusion method. A comparative study of inhibition values of the copolymers and their complexes indicates that the complexes exhibit higher antimicrobial activity. Copper ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium. The nuclease activity of the above metal complexes were assessed by gel electrophoresis assay and the results show that the copper complexes can cleave pUC18 DNA effectively in presence of hydrogen peroxide compared to other metal complexes. The degradation experiments using Rhodamine B dye indicate that the hydroxyl radical species are involved in the DNA cleavage reactions.

• 대한화학회지
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• 제43권3호
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• pp.307-314
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• 1999

대장균의 RNase P의 RNA 성분인 M1 RNA는 대장균 rnpB 유전자의 주요한 일차전사물인 선구-M1 RNA로부터 3'가공으로 생성된다. 이 가공 활성을 가지고 있는 효소 분획을 부분 정제하고 그 특성을 조사하였다. 이 활성 분획을 높은 염농도에 노출시키면 가공 활성이 불활성화하는 것으로 보아, 가공효소는 여러 효소로 이루어진 효소 복합체인 것으로 추정된다. 이 효소 분획은 화학적 핵산 가수분해효소인 납(II) 이온으로 처리하면 효소 활성을 잃지만, 효소 분획 자체에서 추출한 RNA를 가하면 효소 활성을 되찾는다. 이 결과는 효소 활성에는 RNA 분자가 필요하다는 것을 시사한다. 부분 정제한 효소로 형성되는 절단자리들의 분석 결과도, 3'가공과정이 여러 효소에 의하여 일어나고, 적어도 두 가지 다른 경로로 일어난다는 것을 암시한다.

• 농약과학회지
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• 제4권1호
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• pp.32-37
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• 2000

인공핵산 분해효소로서 일련의 3,6-bis(6'-methyl-2'-pyridyl)pyridazine, ($L^{1}$)과 3,6-bis-(2'-pyridyl)pyridazine, ($L^{2}$)을 리간드로 한 몇가지 전이금속 착화합물, $1{\sim}8$을 합성하여 X-ray 결정구조를 확인한 다음, 핵산 모델 화합물과의 가수분해 반응성을 위시하여 논잡초에 대한 살초활성과 식물성 병원균에 대한 살균활성 등을 각각 검토하였다. 그 결과, $L^{2}$-Zn 착물, 8이 무촉매시 보다 빠른 가수분해 반응성을 나타내었으며, 살초활성에서는 $L^{2}$-Ni(II) 및 Co(II) 착물인 5와 6이 벼 (ORY, Oryzar sativa L.)에 대한 선택성을 나타내었을 뿐만 아니라, 올챙이고랭이(SCP, Scriptus juncoids)에 높은 살초활성을 보였다. 그리고 살균활성에서는 $L^{1}$-Co(II) 및 Zn(II) 착물인 2와 4를 위시하여 특히, $L^{1}$ 및 $L^{2}$가 도열병균 MAG (Magnaporthe grisea)에 대하여 90%이상의 살균활성을 나타내었다.

• 한국미생물·생명공학회지
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• 제6권3호
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• pp.121-127
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• 1978

PDase의 생산하는 데에 탄소원으로 sucrose 3% 금속이온으로는 $Ca^{2+}$, Co$^{2+}$, $Mn^{2+}$ 이온등이 좋은 효과를 나타내 주었고 통기는 많을 수록 좋았으며 초기 pH 8의 배지에서 48시간 배양할 때 가장 좋은 결과를 나타내 주었다. 이렇게 하여 생산된 PDase는 pH 8 부근에서 작용온도 6$0^{\circ}C$일 때 최대효소 활성을 나타냈다.

• Animal cells and systems
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• 제2권4호
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• pp.529-538
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• 1998

In order to analyze the intracellu1ar localization of specific RNA components of ribonucleoproteins (RNP) in Xenopus oocytes, a modified protocol of whole-mount in situ Hybridization is presented in this paper, Mitochondria specific 12S rRNA probe was used to detect the amplification and distribution of mitochondria in various stages of the oocyte life cycle, and the results were found to be consistent with previously known distribution of mitochondria. The results with other specific probes (U1 and U3 small nuclear RNAs, and 5S RNA) also indicate that this procedure is generally effective in localizing RNAs in RNP complexes even inside organelles. In addition, the RNA component of RNase MRP, the RNP with endoribo-nuclease activity, localize to the nucleus in various stages of the oocyte life cycle. Some of MRP RNA, however, were found to be localized to the special population of mitochondria near the nucleus, especially in the active stage of mitochondrial amplification. It suggests dual localization of RNase MRP in the nucleus and mitochondria, which is consistent with the proposed roles of RNase MRP in mitochondrial DNA replication and in rRNA processing in the nucleolus.

• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.263-270
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• 2007

New mono- and bis-Cu(II)-triazacyclononane(tacn) complex that conjugated with 9-aminoacridine were synthesized, and their binding modes and DNA cleavage activity were investigated in this study. When the classic intercalator, 9-aminoacridine, was conjugated to mono- and bis-Cu(II)-tacn complexes, a significant red-shift and hypochromism in absorption spectrum was apparent in the acridine absorption region upon binding to DNA. Furthermore, the magnitude of the negative reduced linear dichroism signal in the substrate absorption region appeared to be larger than that in the DNA absorption region. These spectral observations indicated that the acridine moiety intercalated when the Cu(II)-tacn complex was conjugated. In contrast, from a close analysis of the circular and linear dichroism spectrum, the aminoacridine-free bis-Cu(II)-tacn complex was concluded to bind at the phosphate groups of DNA. The 9-aminoacridine-free-bis-Cu(II)-tacn complex produces the nicked and linear DNA. On the other hand, 9-aminoacridine conjugated mono-and bis-Cu(II)-tacn complexes showed unspecific binding with negligible DNA cleavage.