• 약학회지
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• 제42권1호
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• pp.46-52
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• 1998

Retroviral integrase is required for integration of viral DNA into the host cell chromosome. Human immunodeficiency virus type-1 integrase was partially purified as a part of a fusion protein linked to a maltose-binding protein and characterized in terms of an endonucleolytic activity. The concentration of the fusion protein purified through an amylose column was about 12mg/ml. Indicating that the solubility of the fusion protein is highly increased by the presence of a maltose-binding protein, considering that the integrase protein alone is poorly solubilized. The endonucleolytic activity of the fusion protein was detected at 0.1 to 1.OmM $Mn^{++}$ ion, but not at any concentrations tested of $Mn^{++}$ ion.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.82-86
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• 1998

The maltose binding protein (MBP) fusion protein system is a versatile tool to express and isolate recombinant proteins in E. coli. In this system, MBP fusion proteins are efficiently isolated from whole cell lysate using amylose conjugated agarose beads and then eluted by competition with free maltose. Since MBP is a rather large molecule (∼42 kDa), for further experiments, the MBP part is usually proteolytically cleaved from the fusion protein and subsequently removed by ion-exchange chromatography or rebinding to amylose columns after washing out excess and MBP-bound maltose. In the present study, we have developed an improved method for the removal of cleaved MBP, which is advantageous over conventional methods. In this method, factor Xa cleaved MBP fusion proteins were incubated with Sepharose beads conjugated with MBP specific monoclonal antibodies and then precipitated buy centrifugation, resulting in highly purified proteins in the supernatant.

• 산업기술연구
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• 제28권B호
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• pp.59-63
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• 2008

Rapid production of therapeutic proteins such as angiostatin and endostatin angiogenic inhibititors has been highly demanded for cancer treatment. In this regard, recombinant human angiostatin and endostatin were successfully expressed as soluble forms by maltose binding protein (MBP)-mediated fusion expression in Escherichia coli. PCR amplified, angiostatin and endostatin genes from human placenta cDNA library were inserted into an expression vector pMAL-c2e to construct prokaryotic expression vectors, pMAL-c2e/AS and pMAL-c2e/ES, respectively. Recombinant angiostatin and endostatin were efficiently expressed in E. coli origami (DE3) after IPTG induction and protein expression were confirmed by SDS-PAGE analyses. The expressed recombinant proteins were purified near homogenity using an amylose affinty column chromatography. In contrast that previous E. coli expressions were all insoluble, our results first time demonstrated that MBP fused human angiostatin and endostatin were soluble in E. coli.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.89-93
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• 2003

human renin binding protein (hRnBp), showing N-acetylglucosamine-2-epimerase activity, was over-expressed in E. coli, but was mainly present as an inclusion body. To improve its solubility and activity, ubiquitin (Ub), thioredoxin (Trx), maltose binding protein (MBP) and NusA, were used as fusion partners. The comparative solubilities of the fusion proteins were, from most to least soluble: NusA, MBP, Trx, Ub. Only the MBP fusion did not significantly reduce the activity of hRnBp, but enhanced the stability. The Origami (DE3), permitting a more oxidative environment for the cytoplasm in E. coli; helped to increase its functional activity.

• BMB Reports
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• 제31권5호
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• pp.427-431
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• 1998

In the previous report (Choi et al., 1997), the angiogenin binding peptides identified from a phage-peptide library were analyzed by using the fusion proteins composed of the Escherichia coli maltose binding protein and its corresponding peptides. However, it was difficult to obtain a sufficient amount of the fusion proteins required for further analysis because of the low expression level. We now report a high level expression of the fusion protein and analysis of its anti-angiogenin activity. The use of strong T7 promoter and removal of signal sequence allowed about a 20-fold increase in the expression efficiency of the fusion protein. We were able to obtain about 10 mg of purified fusion protein from one liter of culture. The purified fusion protein showed angiogenin-specific affinity and inhibited the binding of biotinylated actin to human angiogenin at $IC_{50}$ of 0.6 mM. Its anti-angiogenin activity was also revealed by the chorioallantoic membrane assay.

• Archives of Pharmacal Research
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• 제22권3호
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• pp.274-278
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• 1999

Expression of the active urease of the enterobacterium, Klebsiella aerogens, requires the presence of the accessory genes (ureD, ureE, ureF, and ureG) in addition to the three structural genes (ureA, ureB, and ureC). These accessory genes are involved in functional assembly of the nickel-metallocenter for the enzyme. Characterization of ureF gene has been hindered, however, since the UreF protein is produced in only minute amount compared to other urease gene products. In order to overexpress the ureF gene, a recombinant pMAL-UreF plasmid was constructed from which the UreF was produced as a fusion with maltose-binding protein. The MBP-UreF fusion protein was purified by using an amylose-affinity column chromatography followed by an anion exchange column chromatography. Polyclonal antibodies raised against the fusion protein were purified and shown to specifically recognize both MBP and UreF peptides. The UreF protein was shown to be unstable when separated from MBP by digestion with factor Xa.

• 한국미생물·생명공학회지
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• 제28권1호
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• pp.21-25
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• 2000

We have got several clones from Serratia marcescens which stimulated the cells to use maltose as a carbon source in Escherichia. coli TP2139 ( lac, crp). One of the cloned genes, pCKB17, was further analyzed. In order to find whether the increased expression of the gent was under the direction of maltose metabolism, we constructed several recombinant subclones. We have found that the clone, pCKB17AV, codes maltose metabolism stimulation(mms) gene. E. coli transformed with the cloned gene showed increase in the activity of maltose utilzation, The recombinant proteins expressed by multicopy and induction with IPTG, one polypeptide of 29-kDa, was confirmed by SDS-PAGE. The overexpression of maltose-binding proter protein in the presence of mms gene was confirmed by Western blot analysis. Southern hybridization analysis confirmed that the cloned DNA fragment was originated from S. marcescens chromosomal DNA.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.183-183
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• 1994

HIV-1 protcase 를 이용한 in vitro assay system을 개발하기 위하여HIV-1 protease유전자를 Ecoli 발현 벡터를 이용하여 발현시켰다. 가능성있는 Protease유전자의 생간 및 분래를 용이하게 하기위하여 maltose binding protein 의 fusion protein을 이용하였으며 protease 의 autoprocessing을 maltose binding protein 의 polyclonal 항체로 확인하였다, 발현된 protease는 일련의 chromatography 방법 (DEAE, SE cellulose, Superose 12, Mono S) 으로 순수하게 분리되었다. 정제된 protease 는 SDS-PAGE분석으로 단일밴드를 보여주었고, 합성된 undecapeptide를 기질로 하였을때 Km 이 9.8$\mu$M 이었다. 효소 assay 를 위해 기질이 protease 에 의해 절단된 생성물을 HPLC를 사용하여 분석하였다. Protease의 억제제 탐색을 위해 유기합성한 몇개의 기질유사체와 HIV-1 증식을 억제하는 것으로 알려진 천연물의 억제정도를 조사하여 보았다. 이들 test 에 사용한 물질들은 높은 농도에서 protease 의 활성을 저해하는 것으로 보아 좋은 억제제는 아닌것으로 시료되나 본 연구를 통하여 확립된 in vitro assay system 은 추후에도 억제제 탐색을 위하여 계속 활용될 수 있을 것이다.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.274-279
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• 2015

Receptor activator of nuclear factor-kappa B ligand (RANKL) is a critical factor in osteoclastogenesis. It makes osteoclasts differentiate and multinucleate in bone remodeling. In the present study, RANKL was expressed as a soluble maltose binding protein (MBP)-fusion protein using the Escherichia coli maltose binding domain tag system (pMAL) expression vector system. The host cell E. coli DH5α was cultured and induced by isopropyl β-_D-1-thiogalactopyranoside for rRANKL expression. Cells were disrupted by sonication to collect soluble MBP-fused rRANKL. The MBP-fusion rRANKL was purified with MBP Trap affinity chromatography and treated with Tobacco Etch Virus nuclear inclusion endopeptidase (TEV protease) to remove the MBP fusion protein. Dialysis was then carried out to remove binding maltose from the cleaved rRANKL solution. The cleaved rRANKL was purified with a second MBP Trap affinity chromatography to separate unsevered MBP-fusion rRANKL and cleaved MBP fusion protein. The purified rRANKL was shown to have biological activity by performing in vitro cell tests. In conclusion, biologically active rRANKL was successfully purified by a simple two-step chromatography purification process with one column.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1002-1010
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• 2001

The D-xylose operon in Escherichia coli is known to be regulated by a transcriptional activator protein, XyIR, which is responsible for the expression of both xylAB and xylFGH gene clusters. The XyIR was purified to homogeneity by using the maltose binding protein fusion expression and purification systems involving two chromatography steps. The purified XyIR protein was composed of two subunits of 45 kDa, which was determined by both sodium dodecyl sulfate polyacrylamide gel electrophoresis and gel filtration. The purified XyIR was specifically bounded to the xylA promoter, regardless of adding xylose to the reaction mixture, but binding of XylR was specifically bounded to the xylA promoter, regardless of adding xylose to the reaction mixture, but binding of XylR to the xylA promoter was enhanced by adding xylose. The enhanced binding ability of XyIR in the presence of xylose was not diminished by adding glucose. The presumed XyIR binding site is located between 120 bp to 100 bp upstream the xylA initiation codon.