• Journal of Plant Biology
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• 제29권4호
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• pp.285-294
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• 1986

The present study was attempted to investigate the effects of polyamines such as putrescine, spermidine and spermine on protein content and DNase activity in vivo and in vitro in carrot embryos. It was also investigated whether polyamines could replace role of cations required for DNase activity in vitro. The results obtained are as follows. Putrescine, spermidine and spermine increased protein content, although response to spermine reached plateau at the concentration of 0.1 mM. DNase activity was inhibited by polyamines, the inhibition being concentration-dependent and the highest att he concentration of 10 mM. The inhibition of DNase activity was the most prominent with spermine. Similar inhibitory effect to polyamines which was concentration-dependent was found in DNase activity but no change was shown on time-course in vitro. Putrescine and spermidine enhanced the DNase activity at low Mg2+ and Mn2+ concentrations, suggesting that the role of Mg2+ and Mn2+ for DNase activity could be, in part, replaced by these polyamines. These results, therefore, suggest that plyamines can modulate DNase activity through binding to DNA rather than direct effect on DNase activity.

• 한국임상수의학회지
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• 제21권3호
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• pp.248-252
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• 2004

DNase activity from infective larvae of the parasitic nematode Haemonchus contortus was characterized and compared to that from whole worm. DNase activity from infective larvae was detected throughout pHs 4-10, but high activity was detected under acidic conditions. The activity was not inhibited by 10 mM EDTA at pH 5.0, but was significantly inhibited at pH 7.0. The activity produced DNA, fragments with mixtures of 3'-hydroxyls (OH) and 3'-phosphates (P) at each pH with predominance of 3'-P. A unique DNase activity at 37 kDa was identified from infective larvae on zymograms. The 37 kDa DNase was detected only at pH 5.0, but not at pH 7.0, and this activity was not inhibited by EDTA at pH 5.0. These characteristics of the 37 kDa infective larval DNase resemble those of classic acidic DNases (e.g., DNase II). In contrast, 34, 36 and 38.5 kDa DNase activities were shown to be specific for whole worm. This result demonstrated that DNases in H contortus are regulated during development.

• Molecules and Cells
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• 제19권1호
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• pp.54-59
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• 2005

Deoxyribonuclease I (DNase I) is a divalent cation dependent endonuclease and thought to be a significant barrier to effective gene delivery. The only known DNase I-specific inhibitor is monomeric actin which acts by forming a 1:1 complex with DNase I. Its use, however, is restricted because of tendency to polymerize under certain conditions. We screened two random phage peptide libraries of complexity $10^8$ and $10^9$ for DNase I binders as candidates for DNase I inhibitors. A number of DNase I-binding peptide sequences were identified. When these peptides were expressed as fusion proteins with Escherichia coli maltose binding protein, they inhibited the actin-DNase I interaction ($IC_{50}=0.1-0.7{\mu}M$) and DNA degradation by DNase I ($IC_{50}=0.8-8{\mu}M$). Plasmid protection activity in the presence of DNase I was also observed with the fusion proteins. These peptides have the potential to be a useful adjuvant for gene therapy using naked DNA.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.348-355
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• 2012

본 연구에서는 S. cerevisiae와 P. pastoris에서 bovine pancreatic (bp-) DNase I의 과발현과 재조합 DNase I의 특성을 조사하였다. bp-DNase I 유전자는 GAL10 promoter, $MF{\alpha}$, GAL7 terminator 사이에 삽입하여 재조합 plasmid인 pGAL-$MF{\alpha}$-DNaseI (6.4 kb)를 구축하였다. 그리고 bp-DNase I 유전자를 AOX1 promoter, $MF{\alpha}$, AOX1 terminator 에 삽입하여 재조합 plasmid인 pPEXI (8.8 kb)를 구축하였다. 재조합 plasmid인 pGAL-$MF{\alpha}$-DNaseI과 pPEXI를 각각 S. cerevisiae와 P. pastoris 숙주세포에 형질전환시켰다. 형질전환된 효모세포들을 galactose와 methanol 배지에서 $30^{\circ}C$, 48시간 배양하면 bp-DNase I은 대부분이 배양 상등액으로 과발현되었다. P. pastoris 형질전환체는 배양 상등액에서 45.5 unit/mL의 DNase I 활성을 보였으며, 반면에 S. cerevisiae 형질전환체는 37.7 unit/mL의 DNase I 활성을 보였다. 또한 DNA 분해 특성을 조사한 결과, P. pastoris 재조합 DNase I으로 기질 DNA(calf thymus)를 처리하였을 때 1분 이내 DNA가 분해되는 것을 확인할 수 있었으며 이는 상업용 bp-DNase I과 S. cerevisiae 재조합 DNase I으로 처리했을 때보다 빠른 분해 패턴을 보였다.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2749-2752
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• 2014

Recent studies have shown that single-stranded DNA adsorbed onto graphene oxide is protected from DNase I cleavage. However, double-stranded DNA bound to graphene oxide and could be digested by DNase I. To elucidate whether single-stranded DNA is protect from DNase I in the presence of graphene oxide, this study conducted DNase I digestion using single-stranded DNA and single-stranded DNA containing the duplex region in the presence of graphene oxide. Addition of DNase I resulted in restoration of the fluorescence emission that had been quenched when DNA was adsorbed to graphene oxide. It indicates that DNase I cleaved the adsorbed single-stranded DNA onto graphene oxide, which was sufficient for the detection of DNase I activity.

• 대한수의학회지
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• 제44권3호
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• pp.441-448
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• 2004

DNase activity in Haemonchus contortus reproductive tissue was characterized and compared to that in whole worm. DNase activity in reproductive tissue was detected throughout pHs 4-10 with high activity under acidic conditions. The activity was not inhibited by 10 mM EDTA at pH 5.0, but largely inhibited by pH 7.0. The activity produced DNA fragments with mixtures of 3'-hydroxyls (OH) and 3'- phosphates (P) at each pH. Three distinct DNase activities were identified and had $M_rs$ of 34, 36 and 38.5 kDa in zymograms, which were distinguished according to pH requirement and sensitivity to EDTA. Among them, the 36 kDa reproductive tissue DNase had predominant activity at pH 5.0, but very weak at pH 7.0, and this activity was not inhibited by EDTA at pH 5.0. These characteristics of the 36 kDa reproductive tissue DNase resemble those of classic acidic DNases. In contrast, 36 kDa whole worm DNase activity had high activity at both pH 5.0 and 7.0. While the 36 kDa DNase activity at pH 5.0 was similar in both reproductive tissue and whole worm samples, the activity at pH 7.0 was predominantly detected in whole worm sample. This suggests that the 36 kDa whole worm DNase at pH 5.0 differs from that at pH 7.0. Thus, results indicate that the EDTA-insensitive 36 kDa DNase at pH 5.0 is specific for H. contortus reproductive tissue.

• 대한화학회지
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• 제29권3호
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• pp.304-310
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• 1985

송아지 흉선 nucleohistone의 DNase 1에 對한 susceptibility와 相互作用의 cooperativity에 미치는 spermine의 效果를 nucleostone의 構造變移와 關聯시켜 調査하였다. 이들 data로 부터 nucleohistone은 遊離 DNA와는 對照的으로 spermine에 의하여 monomoclecular condensation을 일으키지 않고 intermolecular aggregation을 이루며 nucleohistone의 DNase 1과의 相互作用 cooperativity가 spermine에 의하여 增加됨을 推理할 수 있다. Nucleohistine의 histone 部分의 cooperativity에 關한 機能的 役割을 究明하기 위하여 histone 部分을 단실化시킨 DNS-nucleohistone을 製造하여 DNase 1 과의 相互作用을 調査하여 보았는바 negative cooperativity로 나타났다. 이로 부터 nucleohistone의 histone部分은 nucleohistone의 cooperativity에 影響을 미치리라고 推理할 수 있다.

• 대한수의학회지
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• 제44권3호
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• pp.455-462
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• 2004

Change in ${\beta}$-tubulin nucleic acid and protein sequences was the only known difference between Haemonchus contortus fenbendazole (FBZ)-resistant and -susceptible isolates. This change was sufficient to determine the pathologic effect induced by FBZ treatment. This research was initiated to investigate further differences from these two isolates. Since ${\beta}$-tubulin is involved in formation of microtubule, which has functions in secretory vesicle transport, DNase activities from excretory/secretory products (ESP) of the two isolates were compared, based on pH, sensitivity to DNase inhibitors, molecular masses and production of 3'-OH. The most significant difference detected was that a 38.5 kDa DNase activity was identified from ESP of H. contortus FBZ-susceptible isolates but not from those of H. contortus FBZ-resistant isolates. However, it was shown that the 38.5 kDa DNase is expressed with similar level of activity in intestine and whole worm of H. contortus FBZ-resistant and -susceptible isolates. This result demonstrated that the secretory transport pathway of the 38.5 kDa DNase was inhibited by unknown mechanisms, which may be related with ${\beta}$-tubulin sequence change in FBZ-resistant isolates. Other DNases of 34, 36 and 37 kDa were detected from ESP of both H. contortus FBZ-resistant and -susceptible isolates. Overall DNase activities found from ESP of these two isolates were not inhibited by 10 mM EDTA at pH 5.0, but largely inhibited by pH 7.0. In addition, DNase activities in two isolates produced DNA fragments with mixtures of 3'- hydroxyls (OH) and 3'-phosphates (P) at each pH although the 3'-end labeling ratios at pH 5.0 and 7.0 were shown different. Identification of inhibition of the 38.5 kDa DNase secretion in FBZ-resistant isolates suggests existence of further differences, in addition to ${\beta}$-tubulin sequence change, in two isolates. This shows complex effect of FBZ on H. contortus biological mechanisms.

• Journal of Microbiology
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• 제33권3호
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• pp.222-227
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• 1995

We have examined DNase I sensitivity of .betha.-tubulin and flagellar calmodulin genes which are transiently and coordinately activated differentiation of Naegleria gruberi amebae into flagellates. The DNase I sensitivity of .betha.-tubulin and flagellar calmodulin genes changed in parallel with the changes in transcriptional activity of the respective genes during differentiation. The two genes were resistant to DNase I inamebae stage when transcription of the two genes was inactive. Forthy minutes after initiation of differentiation, when the two genes were most actively being transcribed, the two genes showed the highest sensitsivity to DNase I. One hundred and twenty minutes after initiation, the differentiation was completed and transcriptional activity of the two genes decreased to a low level. At this stage, the two genes were resistant to DNase I treatment like the ones at the amebae stage. This change in the DNase I sensitivity of the two genes was not observed when transcription of the two genes was blocked by adding cycloheximide at the beginning of differentiation.

• 대한골관절종양학회지
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• 제7권2호
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• pp.41-50
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• 2001

목적 : 골육종 환자의 조직과 혈청에서 DNase, RNase, 5'-nucleotidase, alkaline phosphatase 및 amylase 활성도를 측정하여 그 활성도의 변동을 보았고 이들 효소가 골육종의 표지자로 이용될 수 있는지 알아보았다. 대상 및 연구방법 : 골육종 환자의 혈청과 종양조직은 1 2예로부터 얻었으며, 이에 대한 대조조직은 동일 환자의 정상부위에서 채취하였다. 조직 추출액을 얻어서 핵산, 단백함량, 그리고 효소 활성도의 측정에 사용하였다. DEAE-cellulose chromatography에 의해 골육종 조직의 acid DNase, neutral RNase, RNase inhibitor와 단백을 분리하고 그활성도와 단백 함량을 측정하였다. 결과 : 골육종 조직의 acid DNase, RNase, 5'-nucleotidase, alkaline phosphatase 활성도는 유의하게 상승하였고, 효소활성도의 양성율도 높게 나타났다. neutral RNase의 활성도가 특히 높았으며, RNase inhibitor는 neutral RNase와 복합을 이루면서 그 활성도가 유의하게 증가하였다. 혈청 neutral RNase 활성도가 유의하게 상승하였다. DEAE-cellulose column chromatography에 의해 acid DNase는 단일효소로서, 그리고 neutral RNase는 5개의 isozyme으로 분리되었다. 결론 : 이들 효소의 병용이 골육종의 생화학적 표지자로서 이용될 수 있을 가능성을 시사하였다. 또한 혈청 neutral RNase활성도의 측정이 골육종의 생화학적 표지자로서의 역할을 시사하였다. acid DNase와 neutral RNase가 골육종의 발생과 억제과정에 작용하고 있을 가능성을 시사하였다.