scholarly journals Expression of Overlapping PreS1 Fragment Recombinant Proteins for the Determination of Immunogenic Domains in HBsAg PreS1 Region

2004 ◽  
Vol 36 (6) ◽  
pp. 397-404 ◽  
Author(s):  
Wei-Guo Hu ◽  
Jun Wei ◽  
Xin-Xiu Yang ◽  
Heng-Chuan Xia ◽  
Feng Li ◽  
...  

Abstract In this study, eight preS1 fragments overlapped in preS1 (21–119) region of HBV adr subtype, i.e. preS1 (21–47), preS1 (34–59), preS1 (48–70), preS1 (60–85), preS1 (71–94), preS1 (86–109), preS1 (95–119) and preS1 (21–119), were cloned by PCR, and expressed as GST fusion proteins. These GST-preS1 fusion proteins were highly expressed in soluble form in E. coli, and about 50 to 90 mg soluble fusion proteins were purified from 1 L culture. Using these fusion proteins, the immunogenic domains in preS1 (21–119) region were identified by Western blot analysis and competitive ELISA. The results showed that the immunogenic domains mainly existed in preS1 (21–59) in N-terminus and preS1 (95–109) in C-terminus, and more importantly, a major immunogenic domain preS1 (34–59), which has much stronger immunogenicity, was identified. It was also supported by the predictions of secondary structure and immunological property in the preS1 (21–119) region. The results here would be helpful for the design of new vaccines against HBV.

2005 ◽  
Vol 70 (12) ◽  
pp. 1401-1407 ◽  
Author(s):  
Sandra Markovic ◽  
Sandra Vojnovic ◽  
Milija Jovanovic ◽  
Branka Vasiljevic

The KgmB methylase from Streptomyces tenebrarius was expressed and purified using the QIAexpress System. Two expression vectors were made: pQEK-N, which places a (His)6 tag at the N-terminus, and pQEK-C, which places a (His)6 tag at the C-terminus of the recombinant KgmB protein. Kanamycin resistance of the E. coli cells containing either the pQEK-N or the pQEK-C recombinant plasmids confirmed the functionality of both KgmB-His fusion proteins in vivo. Interestingly, different levels of expression were observed between these two recombinant proteins. Namely, KgmB methylase with the (His)6 tag at the N-terminus showed a higher level of expression. Purification of the (His)6-tagged proteins using Ni-NTA affinity chromatography was performed under native conditions and the KgmB methylase with (His)6 tag at the N-terminus was purified to homogeneity >95 %. The recombinant KgmB protein was detected on a Western blot using anti-Sgm antibodies.


2018 ◽  
Vol 40 (4) ◽  
Author(s):  
Dang Thi Ngoc Ha ◽  
Le Thi Thu Hong ◽  
Truong Nam Hai

Single chain variable fragments (scFv) have widely been used in research, diagnosis and treatment, but the scFv is considered as difficult protein for expression in E. coli. In previous studies, we expressed a construction of recombinant single chain variable fragments again antigen specific for blood type A (antiA-scFv) individually or fused with Trx or SUMO. However, soluble fraction was low abandant and only approximately 40% when fused with Trx, the other cases were expressed in form of inclusion body. Therefore, it was difficult for purification, refolding and activity assesment. In thispaper, we demonstrated a suitable construction for soluble production of antiA-scFv fused with SUMO (SM/antiA-scFv) in presence of chaparones. Under fermentation with 0.1 mM IPTG at 20oC, the SM/antiA-scFv was entirely expressed in soluble form. Importantly, after cleavage from SUMO with SUMOprotease, antiA-scFv was still maintained in the supernatant fraction. Therefore, it can help ensure bioactivity and is useful for purification process. To the best of our knowledge, this is the first report showing soluble recombinant scFv fused with SUMO in presence of chaperone for determination of blood group antigens. Thus, this result facilitates the optimal study of soluble expression, purification and bioactivity determination of the antiA-scFv recombinant antibody. 


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Young Su Kim ◽  
Hye-Jeong Lee ◽  
Man-ho Han ◽  
Nam-kyung Yoon ◽  
Yeu-chun Kim ◽  
...  

Abstract Background Growth factors (GFs) are signaling proteins that affect cellular processes such as growth, proliferation, and differentiation. GFs are used as cosmeceuticals, exerting anti-wrinkle, anti-aging, and whitening effects, and also as pharmaceuticals to treat wounds, growth failure, and oral mucositis. However, in mammalian and bacterial cells, low productivity and expression in inclusion bodies, respectively, of GFs does not satisfy the consumer demand. Here, we aimed to develop a bacterial expression system that produces high yields of soluble GFs that can be purified in their native forms. Results We present Fh8, an 8-kDa peptide from Fasciola hepatica with an N-terminal hexa-histidine (6HFh8), as a fusion partner for enhanced human GF production in recombinant Escherichia coli. The fusion partner harboring a tobacco etch virus (TEV) protease cleavage site was fused to the N-terminus of 10 human GFs: acidic and basic fibroblast growth factors (aFGF and bFGF, respectively), epidermal growth factor (EGF), human growth hormone (hGH), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor 165 (VEGF165), keratinocyte growth factor 1 (KGF-1), placental growth factor (PGF), stem cell factor (SCF), and tissue inhibitor of metalloproteinase 1 (TIMP-1). The fusion proteins were expressed in E. coli under the control of T7 promoter at three temperatures (25 °C, 30 °C, and 37 °C). All individual fusion proteins, except for SCF and TIMP-1, were successfully overexpressed in cytoplasmic soluble form at more than one temperature. Further, the original aFGF, IGF-1, EGF, and VEGF165 proteins were cleaved from the fusion partner by TEV protease. Five-liter fed-batch fermentation approaches for the 6HFh8-aFGF (lacking disulfide bonds) and 6HFh8-VEGF165 (a cysteine-rich protein) were devised to obtain the target protein at concentrations of 9.7 g/l and 3.4 g/l, respectively. The two GFs were successfully highly purified (> 99% purity). Furthermore, they exerted similar cell proliferative effects as those of their commercial equivalents. Conclusions We demonstrated that 6HFh8-GF fusion proteins could be overexpressed on a g/l scale in the cytoplasm of E. coli, with the GFs subsequently highly purified and maintaining their biological activity. Hence, the small protein 6HFh8 can be used for efficient mass-production of various GFs.


2007 ◽  
Vol 85 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Hongmei Dong ◽  
Xiaohu Xu ◽  
Mohong Deng ◽  
Xiaojun Yu ◽  
Hu Zhao ◽  
...  

The aim of the study was to prepare an active recombinant human perforin by comparing 5 candidate segments of human perforin. Full-length perforin, MAC1 (28–349 aa), MAC2 (166–369 aa), C-100, and N-60 of human perforin were selected as candidate active segments and designated, respectively, HP1, HP2, HP3, HP4, and HP5. The target genes were amplified by PCR and the products were individually subcloned into pGEM-T. The genes for HP1, HP2, HP3, and HP5 were subcloned into pET-DsbA, whereas pET-41a (+) was used as the expression vector of HP4. The fusion proteins were expressed in Escherichia coli BL21pLysS(DE3) and purified using nickel nitrilotriacetic acid (NTA) agarose affinity chromatography. The hemolysis microassay was used as an activity assay of fusion protein. From this study, we obtained the recombinant plasmids pGEM-T-HP1, -HP2, -HP3, -HP4 and -HP5, consisting of 1600, 960, 600, 300bp, and 180, respectively. From these recombinant plasmids, expression plasmids were successfully constructed and expressed in E. coli BL21pLysS(DE3). The resultant fusion proteins, affinity purified using Ni–NTA, were ~80, 58, 45, 44, and 30 kDa, respectively. The recombinant proteins were assayed for activity on hemolysis. HP2 and HP5 were the only recombinant proteins that were active in hemolysis, and the hemolytic function was concentration dependent. These results demonstrate that active recombinant forms of perforin can be synthesized in a prokaryote model. The recombinant N-60 and MAC1 (28–349 aa) of human perforin have the function of forming pores. Our study provides the experimental basis for further investigation on the application of perforin.


Author(s):  
Quang Kien Huynh ◽  
An Hoang Nguyen ◽  
Quynh Thi Mong Pham ◽  
Hoan Phuoc Khai Nguyen ◽  
Hieu Van Tran

Oral vaccine is a strategy being the most interested about treatments of gastrointestinal infections because of many great benefits outweigh conventional injection vaccines. In order to resolve the dispersion of antigens in gastrointestinal surfaces, the immunological tolerance and also be capable to stimulate immune responses effectively, M cells are targeted for antigens delivery. A number of researches reported that 30 amino acids in C terminus of Clostridium perfringens toxin (CPE30) have a high affinity to Claudin-4 receptor presenting on M cells. It is highly indispensable to produce a resource for assessing of CPE30 binding ability so cpe30 gene was cloned into the pET-gfp plasmid by two restriction enzymes BamHI and NdeI on the E. coli DH5α strain. The expression and confirmation of the fusion protein CPE30-GFP which was induced by IPTG in E. coli BL21 (DE3) strain and assessed by SDS-PAGE and Western blot with 6xHis Taq antibody demonstrated that there was the over expression of CPE30 GFP fusion protein in the cytoplasm, mainly in the soluble form. Finally, CPE30-GFP was purified which the purity was approximately 92.3%. In vitro protein interaction measurement using silicon nanowire field-effect transistors (SiNW FETs) showed that CPE30-GFP had a good binding affinity with its receptor Claudin-4 (R4). This result laid the groundwork for the CPE30 interaction study with the M cell in vivo.


2021 ◽  
Author(s):  
Young Su Kim ◽  
Hye-Jeong Lee ◽  
Man-ho Han ◽  
Nam-kyung Yoon ◽  
Yeu-chun Kim ◽  
...  

Abstract Background: Growth factors (GFs) are signaling proteins that affect cellular processes such as growth, proliferation, and differentiation. GFs are used as cosmeceuticals, exerting anti-wrinkle, anti-aging, and whitening effects, and also as pharmaceuticals to treat wounds, growth failure, and oral mucositis. However, in mammalian and bacterial cells, low productivity and expression in inclusion bodies, respectively, of GFs does not satisfy the consumer demand. Here, we aimed to develop a bacterial expression system that produces high yields of soluble GFs that can be purified in their native forms.Results: We present Fh8, an 8-kDa peptide from Fasciola hepatica with an N-terminal hexa-histidine (6HFh8), as a fusion partner for enhanced human GF production in recombinant Escherichia coli. The fusion partner harboring a tobacco etch virus (TEV) protease cleavage site was fused to the N-terminus of 10 human GFs: acidic and basic fibroblast growth factors (aFGF and bFGF, respectively), epidermal growth factor (EGF), human growth hormone (hGH), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor 165 (VEGF165), keratinocyte growth factor 1 (KGF-1), placental growth factor (PGF), stem cell factor (SCF), and tissue inhibitor of metalloproteinase 1 (TIMP-1). The fusion proteins were expressed in E. coli under the control of T7 promoter at three temperatures (25 °C, 30 °C, and 37 °C). All individual fusion proteins, except for SCF and TIMP-1, were successfully overexpressed in cytoplasmic soluble form at more than one temperature. Further, the original aFGF, IGF-1, EGF, and VEGF165 proteins were cleaved from the fusion partner by TEV protease. Five-liter fed-batch fermentation approaches for the 6HFh8-aFGF (lacking disulfide bonds) and 6HFh8-VEGF165 (a cysteine-rich protein) were devised to obtain the target protein at concentrations of 9.7 g/l and 3.4 g/l, respectively. The two GFs were successfully highly purified (>99% purity). Furthermore, they exerted similar cell proliferative effects as those of their commercial equivalents.Conclusions: We demonstrated that 6HFh8-GF fusion proteins could be overexpressed on a g/l scale in the cytoplasm of E. coli, with the GFs subsequently highly purified and maintaining their biological activity. Hence, the small protein 6HFh8 can be used for efficient mass-production of various GFs.


1992 ◽  
Vol 288 (3) ◽  
pp. 1037-1044 ◽  
Author(s):  
R E Milner ◽  
J Busaan ◽  
M Michalak

Dystrophin, the protein product of the Duchenne muscular dystrophy gene, is thought to belong to a family of membrane cytoskeletal proteins. Based on its deduced amino-acid sequence, it is postulated to have several distinct structural domains; an N-terminal region; a central, rod-shaped, domain; and a C-terminal domain [Koenig, Monaco & Kunkel (1988) Cell 53, 219-228]. The C-terminal domain is further divided into two regions; the first has some sequence similarity to slime mould alpha-actinin, and is rich in cysteine residues; this is followed by the C-terminal amino-acid sequence that is unique to dystrophin. Dystrophin is very difficult to purify in quantities sufficient for detailed studies of the structure/function relationships within the molecule. Therefore, in this study, we have expressed selected fragments of the C-terminal region of dystrophin, as fusion proteins, in Escherichia coli. Importantly, we describe the first successful purification, from E. coli lysates, of large quantities of fragments of dystrophin in a soluble form. The first fragment, termed CT-1, encodes the C-terminal 201 amino acids of the protein; the second, termed CT-2, spans the cysteine-rich region of the C-terminal domain. These fusion proteins were identified by their mobility in SDS/PAGE, by their interaction with appropriate affinity columns and by their reactivity with anti-dystrophin antibodies. The fragment CT-2, which spans a region containing putative EF-hand-like sequences, was found to bind Ca2+ in 45Ca2+ overlay experiments. In addition, we have discovered that the fragment CT-1, but not fragment CT-2, interacts specifically with the E. coli DnaK gene product [analogue of heat shock protein 70 (hsp70)]. This interaction is disrupted, in vitro, by the addition of ATP. Our results indicate that the two C-terminal fragments of dystrophin have differing biophysical properties, indicating that they may play distinct roles in the function of the protein.


2002 ◽  
Vol 184 (14) ◽  
pp. 3898-3908 ◽  
Author(s):  
Gareth A. Roberts ◽  
Gideon Grogan ◽  
Andy Greter ◽  
Sabine L. Flitsch ◽  
Nicholas J. Turner

ABSTRACT A degenerate set of PCR primers were used to clone a gene encoding a cytochrome P450 (the P450RhF gene) from Rhodococcus sp. strain NCIMB 9784 which is of unique primary structural organization. Surprisingly, analysis of the translation product revealed that the P450 is fused to a reductase domain at the C terminus which displays sequence conservation for dioxygenase reductase proteins. The reductase partner comprises flavin mononucleotide- and NADH-binding motifs and a [2Fe2S] ferredoxin-like center. The gene was engineered for heterologous expression in Escherichia coli, and conditions were found in which the enzyme was produced in a soluble form. A recombinant strain of E. coli was able to mediate the O dealkylation of 7-ethoxycoumarin in good yield, despite the absence of any recombinant redox proteins. This unprecedented finding leads us to propose that P450RhF represents the first example of a new class of cytochromes P450 in which the reducing equivalents are supplied by a novel reductase in a fused arrangement.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tzu-Yin Lin ◽  
Yu-Hsiu Su ◽  
Kun-Hsiung Lee ◽  
Chin-Kai Chuang

Sense and antisense oligonucleotide pairs encoding cell-penetrating peptides PTD(Tat47–57), DPV3A, E162, pVEC, R11, and TP13 were used to construct two sets of pET22b-CPP-DsRed and pET22b-CPP-J-DsRed vectors for CPP-DsRed and CPP-J-DsRed recombinant proteins expression. PTD-DsRed, DPV3A-DsRed, PTD-J-DsRed, and DPV3A-J-DsRed recombinant proteins were expressed in a soluble form. PTD-J-DsRed and DPV3A-J-DsRed recombinant proteins were able to escape fromE. colihost cells into the culture medium. The membrane-penetrating activity of PTD-J-DsRed and DPV3A-J-DsRed recombinant proteins to mammalian cells was more effective than that of PTD-DsRed and DPV3A-DsRed. The route of the cellular membrane translocation of these recombinant proteins is suggested via macropinocytosis followed by an endosomal escape pathway.


2020 ◽  
Author(s):  
Young Su Kim ◽  
Hye-Jeong Lee ◽  
Man-Ho Han ◽  
Nam-Kyung Yoon ◽  
Yeu-Chun Kim ◽  
...  

Abstract Background: Growth factors (GFs) are signaling proteins that affect cellular processes such as growth, proliferation, and differentiation. GFs are used as cosmeceuticals, exerting anti-wrinkle, anti-aging, and whitening effects, and also as pharmaceuticals to treat wounds, growth failure, and oral mucositis. However, in mammalian and bacterial cells, low productivity and expression in inclusion bodies, respectively, of GFs does not satisfy the consumer demand. Here, we aimed to develop a bacterial expression system that produces high yields of soluble GFs that can be purified in their native forms.Results: We present Fh8, an 8-kDa peptide from Fasciola hepatica with an N-terminal hexa-histidine (6HFh8), as a fusion partner for enhanced human GF production in recombinant Escherichia coli. The fusion partner harboring a tobacco etch virus (TEV) protease cleavage site was fused to the N-terminus of 10 human GFs: acidic and basic fibroblast growth factors (aFGF and bFGF, respectively), epidermal growth factor (EGF), human growth hormone (hGH), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor 165 (VEGF165), keratinocyte growth factor 1 (KGF-1), placental growth factor (PGF), stem cell factor (SCF), and tissue inhibitor of metalloproteinase 1 (TIMP-1). The fusion proteins were expressed in E. coli under the control of T7 promoter at three temperatures (25 °C, 30 °C, and 37 °C). All individual fusion proteins, except for SCF and TIMP-1, were successfully overexpressed in cytoplasmic soluble form at more than one temperature. Further, the original aFGF, IGF-1, EGF, and VEGF165 proteins were cleaved from the fusion partner by TEV protease. Five-liter fed-batch fermentation approaches for the 6HFh8-aFGF (lacking disulfide bonds) and 6HFh8-VEGF165 (a cysteine-rich protein) were devised to obtain the target protein on a g/l scale. The two GFs were successfully highly purified (>99% purity). Furthermore, they exerted similar cell proliferative effects as those of their commercial equivalents.Conclusions: We demonstrated that 6HFh8-GF fusion proteins could be overexpressed on a g/l scale in the cytoplasm of E. coli, with the GFs subsequently highly purified and maintaining their biological activity. Hence, the small protein 6HFh8 can be used for efficient mass-production of various GFs.


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