• Journal of Microbiology
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• 제45권2호
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• pp.175-178
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• 2007

An endonuclease from Xanthomonas oryzae pathovar oryzae KACC 10331, XorII, was recombinantly produced in Escherichia coli using a T7 system. XorII was purified using a combination of ion exchange and immobilized metal affinity chromatography (IMAC). An optimized washing protocol was carried out on an IMAC in order to obtain a high purity product. The final amount of purified XorII was approximately 2.5 mg/L of LB medium. The purified recombinant XorII was functional and showed the same cleavage pattern as PvuI. The enzyme activity tested the highest at $25^{\circ}C$ in 50 mM NaCl, 10 mM Tris-HCl, 10 mM $MgCl_{2}$, and 1 mM dithiothreitol at a pH of 7.9.

• BMB Reports
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• 제43권5호
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• pp.319-324
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• 2010

Experimental bioinformatics data obtained from an E. coli cell-based eukaryotic protein purification experiment were analyzed in order to identify any bottleneck as well as the factors affecting the target purification. All targets were expressed as His-tagged maltose-binding protein (MBP) fusion constructs and were initially purified by immobilized metal affinity chromatography (IMAC). The targets were subsequently separated from the His-tagged MBP through TEV protease cleavage followed by a second IMAC isolation. Of the 743 total purification trials, 342 yielded more than 3 mg of target proteins for structural studies. The major reason for failure of target purification was poor TEV proteolysis. The overall success rate for target purification decreased linearly as cysteine content or isoelectric point (pI) of the target increased. This pattern of pI versus overall success rate strongly suggests that pI should be incorporated into target scoring criteria with a threshold value.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.539-542
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• 2003

SDS-PAGE 결과 elution pH에 따라 분리되는 band pattern은 비슷하게 2band의 양상을 보이지만, FI값을 비교하여 보았을 때 다른 pH보다 8.0에서 가장 높은 수준을 보였으므로 GFPuv/cytochrome c-552 fusion Protein의 분리 ${\cdot}$ 정제에 가장 적합한 pH를 8.0으로 정하였다.

• BMB Reports
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• 제29권2호
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• pp.133-136
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• 1996

The affinity cleavage reagent Methidiumpropyl-EDTA-Iron(II) is applied to the structural analysis of 5S rRNA. Analysis of cleavage sites induced by MPE-Fe(II) on 5S rRNA shows that MPE intercalates easily between the unstable base pairs or into the bulges, thereby it strongly cuts the nucleosides nearby. The stable helical stems A, B, D and E as well as loop d are weakly cut. Most of the single-stranded loops are not cleaved. Based on the cleavage pattern of the 5S rRNA by MPE-Fe(II) and RNase V1, we suggest that MPE-Fe(II) may be used as a potential chemical probe in searching for the unstable helical regions of RNA, and for the sequences that appear to be involved in folding and distorting 5S rRNA.

• Journal of Plant Biology
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• 제18권4호
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• pp.150-154
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• 1975

Four kinds of Nicotiana species and five varieties belonging to N. tabacum were used as materials for electrophoretic analysis of the tetrazolium oxidase isozyme to examine the taxonomic affinity among them based on the biochemical property. All the five verieties of N. tabacum showed same isozyme bands despite the fact that these varieties had notably varied characteristics including morphological traits. The band patterns were more or less different among the four species. Although N. rustica and N. tabacum were of the same genome group of AABB, their isozyme bands showed considerable difference. N. sylvestris, genome A donor of Nicotiana species, was found to be markedly different from N. tatacum in band pattern, including the absence of system 2 in N. sylvestris.

• 한국군사과학기술학회지
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• 제13권1호
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• pp.77-83
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• 2010

In this paper, we proposed new outworn aircraft management procedure. ROKAF has both good management skill and information system, AMMIS, regarding aircraft maintenance based on all kinds of aircraft's defects. To optimize and secure aircraft's operation, management of the outworn aircraft is very important for ROKAF. With respect to these outworn aircraft's defects and maintenance, we analyzed defects occurrence pattern of outworn aircraft by using AMMIS data and Market Basket Analysis, and found the specified association rules for each defect. By using these association rules, we developed new management procedure for outworn aircraft based on the results of affinity analysis. The management procedure in this paper will also be used to optimal operation and maintenance of other aircraft and weapon systems.

• Tuberculosis and Respiratory Diseases
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• 제80권3호
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• pp.255-264
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• 2017

Background:N-acetyl transferase (NAT) inactivates the pro-drug isoniazid (INH) to N-acetyl INH through a process of acetylation, and confers low-level resistance to INH in Mycobacterium tuberculosis (MTB). Similar to NAT of MTB, NAT2 in humans performs the same function of acetylation. Rapid acetylators, may not respond to INH treatment efficiently, and could be a potential risk factor, for the development of INH resistance in humans. Methods: To understand the contribution of NAT of MTB and NAT2 of humans in developing INH resistance using in silico approaches, in this study, the wild type (WT) and mutant (MT)-NATs of MTB, and humans, were modeled and docked, with substrates and product (acetyl CoA, INH, and acetyl INH). The MT models were built, using templates 4BGF of MTB, and 2PFR of humans. Results: On the basis of docking results of MTB-NAT, it can be suggested that in comparison to the WT, binding affinity of MT-G207R, was found to be lower with acetyl CoA, and higher with acetyl-INH and INH. In case of MT-NAT2 from humans, the pattern of score with respect to acetyl CoA and acetyl-INH, was similar to MT-NAT of MTB, but revealed a decrease in INH score. Conclusion: In MTB, MT-NAT revealed high affinity towards acetyl-INH, which can be interpreted as increased formation of acetyl-INH, and therefore, may lead to INH resistance through inactivation of INH. Similarly, in MT-NAT2 (rapid acetylators), acetylation occurs rapidly, serving as a possible risk factor for developing INH resistance in humans.

• 생명과학회지
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• 제18권9호
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• pp.1239-1243
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• 2008

한국산 다람쥐를 단계적으로 $6^{\circ}C$ 온도로 낮추어 인위적 동면을 유도하였다. 동면은 3개월부터 유도되었으며 9개월간 사육하였다. 동면중 급격한 생리적 변화에 따른 형태 및 복합당질의 변화를 관찰하였다. 형태적으로 동면초기 응축된 사구체 구조와 발견되는 것외 동면중에도 유사한 신장 구조를 나타내었다. Lectin조직화학에 대한 반응은 크게 동면초기에 일시적으로 증가하는 반응군, 동면진행에 따라 증가하는 반응군 및 감소하는 반응군으로 대별할 수 있다. 동면초기에 일시적으로 증가하는 반응은 근위곡요세관의 Con A, 원위곡요세관의 PNA, Con A, 집합관의 DBA, sWGA가 현저하였다. 동면이 진행됨에 따라 현저히 증가하는 반응은 원위곡요세관의 SBA반응이었으며, 감소하는 반응은 모든 세관의 sWGA반응이었다. 유사한 형태적 구조를 가지나 다양한 lectin반응의 변화는 동면중 나타나는 급격한 신장 생리 변화와 연관성이 있는 것으로 유추되며, 이러한 반응성은 동면 중 신장 기능 변화에 대한 마크로 유용할 것이다.

• 한국임상수의학회지
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• 제25권5호
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• pp.317-323
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• 2008

Canine trypsin-like immunoreactivity (cTLI), which is a mirror of the concentration of trypsin and trypsinogen, is a pancreas-specific enzyme and a suitable marker for canine pancreatitis and especially exocrine pancreatic insufficiency (EPI). To develop the immunochromatographic test kit, monoclonal antibodies that recognize cTLI were prepared. Anionic trypsin, cationic trypsin, and chymotrypsin from canine pancreas were successfully purified to homogeneity, using ammonium sulfate fractionation and benzamidine-affinity chromatography. The purification fold for anionic trypsin was 108 times when compared with that of the homogenation of pancreas. The molecular weights by SDS-PAGE analysis were approximately 23 kDa for chymotrypsin and approximately 20 kDa for cationic trypsin and anionic trypsin, respectively. Using the purified trypsin-like proteins, ten hybridomas which secret canine trypsin-specific monoclonal antibody were prepared. Klotz plot indicated that hybridomas, 5G2H10G4 and 2F4A11, have high affinity constant (Ka) of $4.1\;{\times}\;10^{9}$ and $1.8\;{\times}\;10^{9}$, respectively. Especially, 5F9H3 showed the cationic typsin-specific binding pattern and its Ka was determined to $4.5\;{\times}\;10^{9}$. The development of immunochromatographic test kit using these monoclonal antibodies against cTLI will be very useful in the diagnosis of canine EPI or canine pancreatitis.

• 한국동물학회지
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• 제32권2호
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• pp.163-175
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• 1989

철 운반 단백질인 Transferrin (Tf)은 계배 근원세포의 분화에 필요한 요소임이 이미 알려져 있다. 따라서 Tf이 작용하는데 필요한 Tf 수용체의 양적 증감은 근원세포의 분화와 깊은 관계가 있을 것으로 생각된다. 본 연구에서는 배양 근원세포의 분화 과정에서 Tf 수용체가 어떠한 변화를 겪는지 알아 보았다. Tf 수용체의 양을 알아보기 위해 세포 표면에 결합되는 125I-Tf의 양을 측정한 결과, Tf 수용체는 근원세포의 분화과정의 하나인 세포융합이 일어나기 약 12시간 전까지 그 양이 증가하다가, 그 이후 근원세포의 분화가 더욱 진행됨에 따라 급격히 감소함을 알 수 있었다. 한편, 근원세포의 융합을 억제하는 여러가지 융합억제제들에 의해서도 그 양이 조절되는 것을 알 수 있었다. 이와 같은 결과들은 통해 근원세포의 분화는 근원세포 표면의 Tf 수용체의 양과 조절되는 것으로 미루어 보아, 생체내에서도 근원세포의 분화에 따라 Tf 수용체의 변화가 있는 것으로 추정되었다.