• 한국식품영양학회지
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• 제17권1호
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• pp.47-52
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• 2004

Mammaglobin은 uteroglobin 유전자와 상동성을 가지는 분비 단백질로 인체 유방암 조직에서 과발현된다. 이 단백질은 유방암의 진단, 전이 정도의 진단, 또는 수술 및 항암치료 후 재발 정도의 검색을 위한 하나의 표식자로 가능성을 갖는다. 본 연구는 mammaglobin 유전자를 클로닝하여, 대장균으로부터 발현하고, 발현된 mammaglobin 단백질을 분리하고, 분리된 단백질을 이용하여 항체를 생산하고, 분리된 항체가 mammaglobin에 대한 특이 반응을 갖는지를 확인하였다. 유방암 환자의 조직을 얻은 후 이 조직에서 RNA를 분리한다. 이 RNA로부터 RT-PCR법으로 mammaglobin 유전자를 클로닝하였다. 증폭된 유전자를 NcoI 과 XhoI으로 절단한 후 벡터에 끼워 넣은 후 대장균에 형질 전환시키고 DNA 염기 서열을 결정하였고, 기존의 mammaglobin 유전자의 염기서열과 비교한 결과 동일한 유전자임을 확인하였다. Mammaglobin의 세포 내 발현, 신호 펩타이드를 이용한 분비발현을 위해 pET30, pET20, pET32 벡터를 각각 이용하였다. 3개의 발현시스템으로부터 단백질이 과 발현됨을 확인할 수 있었다. pET30 벡터를 이용하여 성공적으로 발현된 mammaglobin 단백질을 분리할 수 있었다. Ni-NTA affinity chromatography에 이은 DEAE-ion exchange chromatography 분리 방법에 의해 수용성 발현 단백질인 thioredoxin-mammaglobin을 정제할 수 있었고 이 융합 단백질로부터 enterokinase를 이용하여 mammaglobin 단백질만을 분리하였다. 토끼에 분리된 mammaglobin을 complete adjuvant와 혼합하여 면역한 후 두 번 boosting하여 polyconal 항체를 얻었다. Westernblot immuno 분석을 한 결과 생산된 항체가 mammaglobin 단백질과 특이적 항원항체반응을 보임을 관찰하였다. 향후 이 항체를 이용하여 진단용 시약의 개발이나 항암제 개발 등을 위해 연구가 진행될 것이다.

• BMB Reports
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• 제33권4호
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• pp.294-299
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• 2000

Proteolytic processing of the dengue virus serotype 2 polyprotein precursor is catalyzed by a host signal peptidase and a virus encoded two-component protease consisting of the nonstructural proteins, NS2B and NS3. We expressed in Escherichia coli the NS2B, NS3(pro) and NS2B-NS3 proteins from the dengue virus type 2 strain 16681 as N-terminal fusions with a hexahistidine affinity tag under the control of the inducible trc promoter. All fusion proteins were purified to >90% purity by detergent extraction of inclusion bodies and a single step metal chelate chromatography. Proteins were refolded on-column and recovered with yields of 0.5, 6.0 and 1.0 mg/l of E. coli culture that was grown to $OD_{600}=1.0$ for NS2B, NS3(pro) and NS2B-NS3, respectively. Purified proteins gave strong signals in Western blots using $Ni^{2+}-nitrilotriacetic$ acid as a probe for the presence of the polyHis tag. During the purification process, $(His)_{6}NS2B-NS3$ was apparently not autoproteolytically cleaved at the NS2B/NS3 site.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1310-1315
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• 2019

Hyaluronidases enhance therapeutic drug transport by breaking down the hyaluronan barrier to lymphatic and capillary vessels, facilitating their tissue absorption. Commercially available hyaluronidases are bovine in origin; however, they pose risks such as bovine spongiform encephalopathy. The present study aimed to develop a novel, highly active hyaluronidase and assess its function. Therefore, in order to find the most efficient active hyaluronidase, we produced several shortened hyaluronidases with partial removal of the N- or C-terminal regions. Moreover, we created an enzyme that connected six histidines onto the end of the hyaluronidase C-terminus. This simplified subsequent purification using $Ni^{2+}$ affinity chromatography, making it feasible to industrialize this highly active recombinant hyaluronidase which exhibited catalytic activity equal to that of the commercial enzyme. Therefore, this simple and effective isolation method could increase the availability of recombinant hyaluronidase for research and clinical purposes.

• BMB Reports
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• 제40권1호
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• pp.107-112
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• 2007

To study the functioning of HSP70 in Escherichia coli, we selected NtHSP70-2 (AY372070) from among three genomic clones isolated in Nicotiana tabacum. Recombinant NtHSP70-2, containing a hexahistidine tag at the amino-terminus, was constructed, expressed in E. coli, and purified by $Ni^{2+}$ affinity chromatography and Q Sepharose Fast Flow anion exchange chromatography. The expressed fusion protein, $H_6NtHSP70$-2 (hexahistidine-tagged Nicotiana tabacum heat shock protein 70-2), maintained the stability of E. coli proteins up to 90$^{\circ}C$. Measuring the light scattering of luciferase (luc) revealed that NtHSP70-2 prevents the aggregation of luc without ATP during high-temperature stress. In a functional bioassay (1 h at 50$^{\circ}C$) for recombinant $H_6NtHSP70$-2, E. coli cells overexpressing $H_6NtHSP70$-2 survived about seven times longer than those lacking $H_6NtHSP70$-2. After 2 h at 50$^{\circ}C$, only the E. coli overexpressing $H_6NtHSP70$-2 survived under such conditions. Our NtHSP70-2 bioassays, as well as in vitro studies, strongly suggest that HSP70 confers thermo-tolerance to E. coli.

• 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.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2405-2409
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• 2011

The psychrophilic bacteria Psychromonas arctica survives at subzero temperatures by having adapted several protective mechanisms against freezing and oxidative stresses. Many reactive oxygen species are likely generated in P. arctica as a result of reduced metabolic turnover rates. A previous study identified the pasod gene for superoxide dismutase from P. arctica using a series of PCR amplifications. Here, upon cloning into a His-tag fused plasmid, the sod gene from P. arctica (pasod) was successfully expressed by IPTG induction. His-tagged PaSOD was subsequently purified by $Ni^{2+}$-NTA affinity chromatography. The purified PaSOD exhibited a higher SOD activity than that of Escherichia coli (EcSOD) at all temperatures. The difference in activity between PaSOD and EcSOD becomes even more significant at 4$^{\circ}C$, indicating that PaSOD plays a functional role in the cold adaptation of P. arctica in the Arctic.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.86-89
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• 1997

Epidermal growth factor(EGF) known as a urgastrone is a powerful mitogen with a wide variety of possibilities for medical usages. A mature EGF coding region was isolated from human prepro-EGF sequence by a conventional PCR and cloned into pQE vector in which the gene product was supposed to be expressed with 6$\times$His tag for the subsequent purification. The recombinant mature EGF was expressed in M15[Rep4], an Escherichia coli host strain, in amount of 30-40% of total proteins pressent in E. coli extract by the addition of isopropylthio-$\beta$-galactopyranoside (IPTG). The recombinant EGF purified using a Ni2+-NTA affinity colume chromatography was active in its ability to induce phosphorylation on tyrosine residues of several substrate proteins when murine NH3T3 and human MRC-5 fibroblast cells were stimulated with it. This work may provide the basic technology and information for the production of recombinant EGF.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.681-684
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• 2007

An immunoassay method was developed to quantitatively detect phosphinothricin-N-acetyltransferase (PAT) encoded by the Bialaphos resistance (bar) gene in genetically modified (GM) pepper. The histidine-tagged PAT was overexpressed in Escherichia coli M15 (pQE3l-bar) and efficiently purified by $Ni^{2+}$ affinity chromatography. A developed sandwich enzyme-linked immunosorbent assay (S-ELISA) method (detection limit: $0.01{\mu}g/ml$) was 100-fold more sensitive than a competitive indirect ELISA (CI-ELISA) method or Western blot analysis in detecting the recombinant PAT. In real sample tests, PAT in genetically modified herbicide-tolerant (GMHT) peppers was successfully quantified [$4.9{\pm}0.4{\mu}g/g$ of sample (n=6)] by the S-ELISA method. The S-ELISA method developed here could be applied to other GMHT crops and vegetables producing PAT.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.52-52
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• 2001

Nickel-binding protein (NBP1) was purified from the crude extract of Streptomyces seoulensis using Ni$^{2＋}$-charged metal chelate affinity chromatography. The molecular mass of NBPI determined on SDS-PAGE was 38kDa. An approximately 3 kb DNA fragment containing the structural gene for NBP1 was cloned from lEMBL3 genomic library of S. seoulensis using a DNA fragment PCR-amplified with the primers designed from N-terminal and internal amino acid sequences of NBP1.(omitted)

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.128.1-128.1
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• 2007

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