scholarly journals Biologically active and amidated cecropin produced in a baculovirus expression system from a fusion construct containing the antibody-binding part of protein A

1991 ◽  
Vol 280 (1) ◽  
pp. 219-224 ◽  
Author(s):  
D Andersons ◽  
Å Engström ◽  
S Josephson ◽  
L Hansson ◽  
H Steiner

A synthetic antibody-binding part derived from protein A from Staphylococcus aureus was used as a fusion partner in a eukaryotic expression system employing Autographa californica nuclear polyhedrosis as a vector. This, in conjunction with an efficient signal sequence, facilitated the purification of the antibacterial peptide cecropin A from the medium of Spodoptera frugiperda cells infected with a recombinant virus. In order to increase further the concentrations of fusion protein, Trichoplusia ni larvae were used as host. Cecropin A could be obtained after cleavage of the fusion protein with CNBr. Biological activity as well as the correct structure including the C-terminal amide group was shown using electrophoresis with detection of antibacterial proteins and mass spectroscopy.

2021 ◽  
Vol 9 (9) ◽  
pp. 1858
Author(s):  
Yingli Zhang ◽  
Zhongchen Li ◽  
Li Li ◽  
Ben Rao ◽  
Lixin Ma ◽  
...  

In this study, a method for the rapid screening, expression and purification of antimicrobial peptides (AMPs) was developed. AMP genes were fused to a heat-resistant CL7 tag using the SLOPE method, and cloned into Escherichia coli and Pichia pastoris expression vectors. Twenty E. coli and ten P. pastoris expression vectors were constructed. Expression supernatants were heated, heteroproteins were removed, and fusion proteins were purified by nickel affinity (Ni-NTA) chromatography. Fusion proteins were digested on the column using human rhinovirus (HRV) 3C protease, and AMPs were released and further purified. Five AMPs (1, 2, 6, 13, 16) were purified using the E. coli expression system, and one AMP (13) was purified using the P. pastoris expression system. Inhibition zone and minimum inhibitory concentration (MIC) tests confirmed that one P. pastoris¬-derived and two E. coli-derived AMPs have the inhibition activity. The MIC of AMP 13 and 16 from E. coli was 24.2 μM, and the MIC of AMP 13 from P. pastoris was 8.1 μM. The combination of prokaryotic and eukaryotic expression systems expands the universality of the developed method, facilitating screening of a large number of biologically active AMPs, establishing an AMP library, and producing AMPs by industrialised biological methods.


2000 ◽  
Vol 66 (2) ◽  
pp. 638-642 ◽  
Author(s):  
Tsutomu Kajino ◽  
Chikara Ohto ◽  
Masayoshi Muramatsu ◽  
Shusei Obata ◽  
Shigezo Udaka ◽  
...  

ABSTRACT We have developed a versatile Bacillus brevisexpression and secretion system based on the use of fungal protein disulfide isomerase (PDI) as a gene fusion partner. Fusion with PDI increased the extracellular production of heterologous proteins (light chain of immunoglobulin G, 8-fold; geranylgeranyl pyrophosphate synthase, 12-fold). Linkage to PDI prevented the aggregation of the secreted proteins, resulting in high-level accumulation of fusion proteins in soluble and biologically active forms. We also show that the disulfide isomerase activity of PDI in a fusion protein is responsible for the suppression of the aggregation of the protein with intradisulfide, whereas aggregation of the protein without intradisulfide was prevented even when the protein was fused to a mutant PDI whose two active sites were disrupted, suggesting that another PDI function, such as chaperone-like activity, synergistically prevented the aggregation of heterologous proteins in the PDI fusion expression system.


2006 ◽  
Vol 53 (2) ◽  
pp. 361-369 ◽  
Author(s):  
Eliza P Kwiatkowska ◽  
Urszula Kazimierczak ◽  
Andrzej Mackiewicz ◽  
Dariusz W Kowalczyk

We have constructed and expressed recombinant chimeric soluble TGF-beta type II receptor fused with the Fc portion of human IgG1 (sTbetaRII-Fc) in NS0 mouse myeloma cells and isolated cell lines constitutively secreting very high levels of biologically active protein. The GS-NS0 expression system takes advantage of the strong human cytomegalovirus immediate early promoter expression vector and glutamine synthetase as a selectable marker. The recombinant chimeric receptor could be produced in high amounts and efficiently purified by one step chromatography on a protein A column. Biochemical studies revealed that recombinant sTbetaRII-Fc binds native TGF-beta1 and TGF-beta3 isoforms and neutralizes their activity in vitro.


2015 ◽  
Vol 40 (4) ◽  
Author(s):  
Ömer İrfan Küfrevioğlu ◽  
Emrah Yerlikaya ◽  
Orhan Erdoğan ◽  
Ramazan Demirdağ ◽  
Murat Şentürk

AbstractObjective: In this study, investigating the effects of inhibition of the enzyme activity of some antitumor drugs and the Cancer-Related Human Carbonic Anhydrase IX (hCA IX) isoenzyme expressing as a SUMO fusion protein in an Escherichia coli expression system were aimed.Methods: hCA IX isoenzyme was expressed using SUMO fusion technology. The fusion protein was expressed in a totally soluble form and the expression was verified by SDS-PAGE analysis. Affinity chromatography was used in the purification processes. The effects of certain antitumor drugs on enzyme activity were investigated in vitro conditions by using esterase activity. ICResults: The molecular weight of the fusion protein was approximately 85kDa. The optimal induction concentration of IPTG and the growth temperature were found to be 1.0mM and 30°C. The fusion protein was purified at approximately 3.07-fold with a yield of 92.58%, and a specific activity of 43707EU/mg proteins by nickel nitrilo-triacetic acid resin chromatography.Conclusion: Our work is extremely important because CA IX plays a clinical role as a biomarker in cancer diagnosis and the use of specific inhibitors of the CA IX enzyme will be useful in the fight against cancer. In vitro inhibition studies on the recombinant hCA IX enzyme can shed light on the development of anticancer drugs for cancers overexpressing CA IX.


Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3977-3986 ◽  
Author(s):  
Satarupa Roy ◽  
Sunita Setlur ◽  
Rupali A. Gadkari ◽  
H. N. Krishnamurthy ◽  
Rajan R. Dighe

The strategy of translationally fusing the α- and β-subunits of human chorionic gonadotropin (hCG) into a single-chain molecule has been used to produce novel analogs of hCG. Previously we reported expression of a biologically active single-chain analog hCGαβ expressed using Pichia expression system. Using the same expression system, another analog, in which the α-subunit was replaced with the second β-subunit, was expressed (hCGββ) and purified. hCGββ could bind to LH receptor with an affinity three times lower than that of hCG but failed to elicit any response. However, it could inhibit response to the hormone in vitro in a dose-dependent manner. Furthermore, it inhibited response to hCG in vivo indicating the antagonistic nature of the analog. However, it was unable to inhibit human FSH binding or response to human FSH, indicating the specificity of the effect. Characterization of hCGαβ and hCGββ using immunological tools showed alterations in the conformation of some of the epitopes, whereas others were unaltered. Unlike hCG, hCGββ interacts with two LH receptor molecules. These studies demonstrate that the presence of the second β-subunit in the single-chain molecule generated a structure that can be recognized by the receptor. However, due to the absence of α-subunit, the molecule is unable to elicit response. The strategy of fusing two β-subunits of glycoprotein hormones can be used to produce antagonists of these hormones.


Endocrinology ◽  
1997 ◽  
Vol 138 (2) ◽  
pp. 588-593 ◽  
Author(s):  
Y. Bobovnikova ◽  
P. N. Graves ◽  
H. Vlase ◽  
T. F. Davies

Abstract To study the interaction of TSH receptor (TSHR) autoantibodies with receptor protein, it is necessary first to express the receptor in the proper conformation including the formation of correct disulfide bridges. However, the reducing environment of the Escherichia coli (E. coli) cytoplasm prevents the generation of protein disulfide bonds and limits the solubility and immunoreactivity of recombinant human TSHR (hTSHR) products. To circumvent these limitations, hTSHR complementary DNA encoding the extracellular domain (hTSHR-ecd; amino acids 21–415) was inserted into the vector pGEX-2TK by directional cloning and used to transform the thioredoxin reductase mutant strain of E. coli (Ad494), which allowed formation of disulfide bonds in the cytoplasm. After induction, the expressed soluble hTSHR-ecd fusion protein was detected by Western blot analysis using a monoclonal antibody directed against hTSHR amino acids 21–35. This showed that over 50% of the expressed hTSHR-ecd was soluble in contrast to expression in a wild-type E. coli (strain αF′), where the majority of the recombinant receptor was insoluble. The soluble recombinant receptor was affinity purified and characterized. Under nonreducing SDS-PAGE conditions, the soluble hTSHR-ecd migrated as refolded, disulfide bond-stabilized, multimeric species, whose formation was independent of fusion partner protein. This product was found to be biologically active as evidenced by the inhibition of the binding of 125I-TSH to the full-length hTSHR expressed in transfected CHO cells and was used to develop a competitive capture enzyme-linked immunosorbent assay for mapping of hTSHR antibody epitopes. Hence, hTSHR-ecd produced in bacteria with a thioredoxin reductase mutation was found to be highly soluble and biologically relevant.


2015 ◽  
Vol 41 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Kounosuke Hayashi ◽  
Yusuke Tomozoe ◽  
Kenji Nagai ◽  
Kyoichi Matsuba ◽  
Masayuki Mitsumori ◽  
...  

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