• Journal of Applied Biological Chemistry
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• 제43권1호
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• pp.1-4
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• 2000

Chloramphenicol acetyl CoA transferase (CAT) and angiotensin- converting enzyme inhibitory peptide (ACEI) were fused to C-terminal region of rice ubiquitin to examine the level of transcripts or enzyme activities in yeast. When two chimeric genes under an inducible Gall promoter control were transformed into Saccharomyces cerevisaie, both CAT and ACE inhibitory activities were enhanced by three to four-fold as compared to those containing no ubiquitin gene. However, the levels of transcripts of ubiquitin fused and un fused genes were not significantly different each other. Therefore, it was suggested that the expression of foreign genes was post-transcriptionally enhanced by fusion of plant ubiquitin in heterologous organisms such as yeast.

• Bulletin of the Korean Chemical Society
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• 제28권9호
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• pp.1549-1552
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• 2007

The cytoplasmic domain of syndecan-4, a type I transmembrane heparan sulfate proteoglycan, was overexpressed as a fused form with the ubiquitin molecule in Escherichia coli, and the fusion protein was purified using immobilized metal affinity chromatography (IMAC). The cytoplasmic domain was released from its fusion partner by using yeast ubiquitin hydrolase (YUH), and subsequently purified by reverse phase chromatography. The integrity of the resulting peptide fragment was checked by MALDI-TOF and NMR spectroscopy. The yield of the peptide was 3.0-1.5 mg per liter in LB or minimal medium, respectively. The recombinant expression and purification of this domain will enable us its structural and functional studies using multidimensional NMR spectroscopy.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.554-556
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• 2003

본 연구에서는 고부가가치 의약단백질인 human growth hormone을 고순도로 얻기 위하여 재조합 대장균을 이용하여 ubiquitin이 융합된 형태로 단백질을 발현시키고, 이를 분해하는 ubiquitin-specific pretense를 발현시켜 이를 분리 ${\cdot}$ 정제하고 효소특성을 살펴보았다. UBP1 enzyme을 재조합 대장균을 이용하여 발현하고 분리 ${\cdot}$ 정제한 결과, 분자량은 약 83.5kDa이었으며, $40^{\circ}C$, pH 8.0에서 최대 효소활성을 보였다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4337-4340
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• 2011

The vitamin D receptor binding peptide, VDRBP, was overexpressed as a fused form with the ubiquitin molecule in Rosetta(DE3)pLysS, a protein production strain of Escherichia coli harboring an induction controller plasmid. The fusion protein was bound to the immobilized metal ions, and the denaturation and renaturation of the fusion protein were performed as a part of the purification procedure. After the elution of the fusion protein, the peptide hormone was released from its fusion partner by using yeast ubiquitin hydrolase (YUH), and subsequently purified by reverse phase chromatography. The purity of the resulting peptide fragment was checked by MALDI-TOF mass and NMR spectroscopy. The final yields of the target peptide were around 5 and 2 mg per liter of LB and minimal media, respectively. The recombinant expression and purification of this peptide will enable structural and functional studies using multidimensional NMR spectroscopy and X-ray crystallography.

• BMB Reports
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• 제41권12호
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• pp.852-857
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• 2008

Little attention has been paid to the specificity between E2 and the target protein during ubiquitination, although RING-E3 induces a potential intra-molecular reaction by mediating the direct transfer of ubiquitin from E2 to the target protein. We have constructed artificial E2 fusion proteins in which a target protein (p27) is tethered to one of six E2s via a flexible linker. Interestingly, only three E2s (UbcH5b, hHR6b, and Cdc34) are able to ubiquitinate p27 via an intra-molecular reaction in this system. Although the first ubiquitination of p27 (p27-Ub) by Cdc34 is less efficient than that of UbcH5b and hHR6b, the additional ubiquitin attachment to p27-Ub by Cdc34 is highly efficient. The E2 core of Cdc34 provides specificity to p27, and the residues 184-196 are required for possessive ubiquitination by Cdc34. We demonstrate direct E2 specificity for p27 and also show that differential ubiquitin linkages can be dependent on E2 alone.

• 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.

• Korean Chemical Engineering Research
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• 제56권5호
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• pp.711-717
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• 2018

상피세포 성장인자(Epidermal Growth Factor, EGF)는 세포 분열을 자극하고 의약적 용도가 다양하다. EGF는 3개의 이황화 결합을 갖고 불용성으로, 대장균에서 고효율 발현에 대한 연구가 잘 이루어지지 않았다. EGF 유전자를 작은 유비퀴틴 관련 유전자(small ubiquitin-related modifier gene, SUMO)와 결합하고 DE3 대장균에서 발현시켰다. IPTG (Isopropyl-${\beta}$-D-Thiogalactopyranoside)로 유도하여 대장균 세포 단백질의 38.9%로 융합단백질이 발현되었고, Ni-NTA 친화성 크로마토그래피로 분리하였다. 그 후 유비퀴틴 분해효소반응으로 융합단백질에서 EGF를 얻은 후 다시 Ni-NTA 크로마토그래피로 분리 하였다. 최종적으로 정제된 EGF의 순도는 HPLC로 분석하였으며, 98%이상의 순도를 얻을 수 있었다.

• 농업과학연구
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• 제41권3호
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• pp.237-243
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• 2014

Human Glucagon like peptide-1 (GLP-1) is an incretin hormone that promotes secretion of insulin. In order to eliminate the formation of the soluble aggregate, Ala19 in GLP-1 was substituted with Thr, resulting in a GLP-1 mutant GLP-1A19T. The gene synthesis of GLP-1A19T and the fusion of 6-lysine tagged ubiquitin gene were accomplished by using the overlap extension polymerase chain reaction. The ubiquitin fused GLP-1A19T (K6UbGLP-1A19T) is expressed as form of inclusion body with little formation of the soluble aggregation in recombinant E. coli. In order to produce K6UbGLP-1A19T in large amounts, fed-batch fermentation was carried out in a pH-stat feeding strategy. Maximum dry cell weight of 87.7 g/L and 20.4% of specific K6UbGLP-1A19T content were obtained. Solid-phase refolding using a cation exchanger was carried out to renature K6UbGLP-1A19T. The refolded K6UbGLP-1A19T aggregated little and was released GLP-1A19T by on-column cleavage with ubiquitin-specific protease-1. The molecular mass of GLP-1A19T showed an accurate agreement with its theoretical molecular mass.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.952-959
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• 2007

His-His-Leu (HHL), a tripeptide derived from a Korean soybean paste, is an angiotensin-I-converting enzyme (ACE) inhibitor. We report here a method of producing this tripeptide efficiently by expressing tandem multimers of the codons encoding the peptide in E. coli and purifying the HHL after hydrolysis of the peptide multimers. The HHL gene, tandemly multimerized to a 40-mer, was ligated with ubiquitin as a fusion gene (UH40). UH40 was inserted into vector pET29b; the UH40 fusion protein was then produced in E. coli BL21. The recombinant UH40 protein was purified by cation-exchange chromatography with a yield of 17.3mg/l and analyzed by matrixassisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry and protein N-terminal sequencing. Leucine aminopeptidase was used to cleave a 405-Da HHL monomer from the UH40 fusion protein and the peptide was purified using reverse-phase high-performance liquid chromatography (HPLC) on a C18 HPLC column, with a final yield of 6.2mg/l. The resulting peptide was confirmed to be HHL with the aid of MALDI-TOF mass spectrometry, glutamine-TOF mass spectrometry, N-terminal sequencing, and measurement of ACE inhibiting activity. These results suggest that our production method is useful for obtaining a large quantity of recombinant HHL for functional antihypertensive peptide studies.

• International Journal of Industrial Entomology and Biomaterials
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• 제32권2호
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• pp.90-97
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• 2016

The major structural proteins of porcine reproductive and respiratory syndrome virus (PRRSV) are derived from ORFs 4, 5, and 6. They have been considered very important to arouse the humoral and cellular immune responses against PRRSV infection and proposed to be the excellent candidate proteins in the design of PRRS bioengineering vaccine. However, the PRRSV structural proteins are produced in low levels in the infected cells because it forms insoluble protein and possesses several transmembrane regions. To overcome this problem, we fused the ORF4, ORF5, and ORF6 with SUMO (small ubiquitin-related modifier). The resulting fusion protein SUMO-ORF4, -ORF5, and -ORF6 were highly expressed in Bm5 cells. The level of protein expression using the Bombyx mori larvae was higher than that using Bm5 cells. In addition, fusion to SUMOstar, which is not processed by native SUMO proteases, significantly enhanced protein expression levels compared to SUMO fusion. This study demonstrated that SUMO or SUMOstar, when fused with PRRSV structural proteins, was able to promote its soluble expression. This may be a better method to produce PRRSV structural proteins for vaccine development.