scholarly journals A Method for Rapid Screening, Expression, and Purification of Antimicrobial Peptides

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.

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Nagendra Suryanarayana ◽  
Vanlalhmuaka ◽  
Bharti Mankere ◽  
Monika Verma ◽  
Kulanthaivel Thavachelvam ◽  
...  

Bacillus anthracis secretory protein protective antigen (PA) is primary candidate for subunit vaccine against anthrax. Attempts to obtain large quantity of PA from Escherichia coli expression system often result in the formation of insoluble inclusion bodies. Therefore, it is always better to produce recombinant proteins in a soluble form. In the present study, we have obtained biologically active recombinant PA in small scale E. coli shake culture system using three different expression constructs. The PA gene was cloned in expression vectors bearing trc, T5, and T7 promoters and transformed into their respective E. coli hosts. The growth conditions were optimized to obtain maximum expression of PA in soluble form. The expression construct PA-pET32c in DE3-pLysS E. coli host resulted in a maximum production of soluble PA (15 mg L−1) compared to other combinations. Purified PA was subjected to trypsin digestion and binding assay with lethal factor to confirm the protein’s functionality. Biological activity was confirmed by cytotoxicity assay on J774.1 cells. Balb/c mice were immunized with PA and the immunogenicity was tested by ELISA and toxin neutralization assay. This study highlights the expression of soluble and biologically active recombinant PA in larger quantity using simpler E. coli production platform.


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.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jan Weber ◽  
Zhaopeng Li ◽  
Ursula Rinas

Abstract Background Recently it was shown that production of recombinant proteins in E. coli BL21(DE3) using pET based expression vectors leads to metabolic stress comparable to a carbon overfeeding response. Opposite to original expectations generation of energy as well as catabolic provision of precursor metabolites were excluded as limiting factors for growth and protein production. On the contrary, accumulation of ATP and precursor metabolites revealed their ample formation but insufficient withdrawal as a result of protein production mediated constraints in anabolic pathways. Thus, not limitation but excess of energy and precursor metabolites were identified as being connected to the protein production associated metabolic burden. Results Here we show that the protein production associated accumulation of energy and catabolic precursor metabolites is not unique to E. coli BL21(DE3) but also occurs in E. coli K12. Most notably, it was demonstrated that the IPTG-induced production of hFGF-2 using a tac-promoter based expression vector in the E. coli K12 strain TG1 was leading to persistent accumulation of key regulatory molecules such as ATP, fructose-1,6-bisphosphate and pyruvate. Conclusions Excessive energy generation, respectively, accumulation of ATP during recombinant protein production is not unique to the BL21(DE3)/T7 promoter based expression system but also observed in the E. coli K12 strain TG1 using another promoter/vector combination. These findings confirm that energy is not a limiting factor for recombinant protein production. Moreover, the data also show that an accelerated glycolytic pathway flux aggravates the protein production associated “metabolic burden”. Under conditions of compromised anabolic capacities cells are not able to reorganize their metabolic enzyme repertoire as required for reduced carbon processing.


2015 ◽  
Vol 102 ◽  
pp. 14-17 ◽  
Author(s):  
Syed Sajitha ◽  
Jalaja Vidya ◽  
karunakaran Varsha ◽  
Parameswaran Binod ◽  
Ashok Pandey

2013 ◽  
Vol 5 (3) ◽  
pp. 499-513
Author(s):  
M. Z. Alam ◽  
L. Ragionieri ◽  
M. A. S. Santos ◽  
A. Iqbal

Enzymes and other protein purification using recombinant DNA technology have become popular due to scarcity of natural protein. Saccharomyces cerevisiae is a demanding host, since it facilitates protein expression by its relative simplicity, safe organisms, inexpensive and has many properties of eukaryotic expression system. As an alternative host we express E. coli lacZ gene with GST tag in Saccharomyces cerevisiae and successfully purified from soluble extracts. The concentration of soluble GST-? galactosidase protein was approximately 0.57 mg/ml of elution buffer yielded from 50 ml yeast cell culture. The ?-galactosidase protein from insoluble extract was low due to the increasing solubility of GST tag. Keywords: ?-galactosidase; Heterologous expression; GST tag; Affinity chromatography. © 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v5i3.13820 J. Sci. Res. 5 (3), 499-513 (2013)  


Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 509 ◽  
Author(s):  
Min-Chao Jiang ◽  
Chung-Chi Hu ◽  
Na-Sheng Lin ◽  
Yau-Heiu Hsu

Plant-based systems are safe alternatives to the current platforms for the production of biologically active therapeutic proteins. However, plant-based expression systems face certain major challenges, including the relatively low productivity and the generation of target proteins in biologically active forms. The use of plant virus-based expression systems has been shown to enhance yields, but further improvement is still required to lower the production cost. In this study, various strategies were employed to increase the yields of an important therapeutic protein, human interferon gamma (IFNγ), in Nicotiana benthamiana through modifications of expression vectors based on potexviruses. Among these, the vector based on a coat protein (CP)-deficient Bamboo mosaic virus (BaMV), pKB△CHis, was shown to exhibit the highest expression level for the unmodified IFNγ. Truncation of the N-terminal signal peptide of IFN (designated mIFNγ) resulted in a nearly seven-fold increase in yield. Co-expression of a silencing suppressor protein by replacing the coding sequence of BaMV movement protein with that of P19 led to a 40% increase in mIFNγ accumulation. The fusion of endoplasmic reticulum (ER) retention signal with mIFNγ significantly enhanced the accumulation ratio of biologically active dimeric mIFNγ to 87% relative to the non-active monomeric form. The construct pKB19mIFNγER, employing the combination of all the above enhancement strategies, gave the highest level of protein accumulation, up to 119 ± 0.8 μg/g fresh weight, accounting for 2.5% of total soluble protein (TSP) content. These findings advocate the application of the modified BaMV-based vector as a platform for high-level expression of therapeutic protein in N. benthamiana.


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.


2003 ◽  
Vol 27 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Wendy Bagnall ◽  
Paul M Sharpe ◽  
Peter Newham ◽  
Johnathan Tart ◽  
Richard A Mott ◽  
...  

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