scholarly journals Metabolomic analysis of riboswitch containing E. coli recombinant expression system

2016 ◽  
Vol 12 (2) ◽  
pp. 350-361 ◽  
Author(s):  
Howbeer Muhamadali ◽  
Yun Xu ◽  
Rosa Morra ◽  
Drupad K. Trivedi ◽  
Nicholas J. W. Rattray ◽  
...  

In this study we have employed metabolomics approaches to understand the metabolic effects of producing enhanced green fluorescent protein (eGFP) as a recombinant protein inEscherichia colicells.

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2156
Author(s):  
Mizozoe ◽  
Otaki ◽  
Aikawa

This study investigated how chlorine inactivates and damages Escherichia coli cells. E. coli that had transformed to express enhanced green fluorescent protein (EGFP) at the cytoplasm was treated with chlorine. Damage to the cell membrane and cell wall was analyzed by measuring the fluorescence intensity of the leaked EGFP, then accounting for the fluorescence deterioration. At pH 7, E. coli was lethally damaged after treatment with chlorine, but significant leakage of EGFP was not observed. In contrast, significant leakage of EGFP was observed at pH 9, even though E. coli was not as inactivated as it was at pH 7. Flow cytometry was used to confirm the fluorescence intensity of the remaining EGFP inside the cells. No significant fluorescence loss was observed in the cells at pH 7. However, at pH 9, the fluorescence intensity in the cells decreased, indicating leakage of EGFP. These results suggest that hypochlorous acid inactivates E. coli without damaging its cell membrane and cell wall, whereas the hypochlorite ion inactivates E. coli by damaging its cell membrane and cell wall. It was possible to confirm the chlorine damage mechanism on E. coli by measuring the fluorescence intensity of the leaked EGFP.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Fatemeh Sadat Shariati ◽  
Dariush Norouzian ◽  
Vahideh Valizadeh ◽  
Reza Ahangari Cohan ◽  
Malihe Keramati

Abstract Background Identification of high-expressing colonies is one of the main concerns in the upstream process of recombinant protein development. The common method to screen high-producing colonies is SDS-PAGE, a laborious and time-consuming process, which is based on a random and qualitative way. The current study describes the design and development of a rapid screening system composed of a dicistronic expression system containing a reporter (enhanced green fluorescent protein, eGFP), protein model (staphylokinase, SAK), and a self-inducible system containing heat shock protein 27 (Hsp27). Results Dicistronic-autoinducible system expressed eGFP and SAK successfully in 5-ml and 1-L culture volumes. High expressing colonies were identified during 6 h via fluorescent signals. In addition, the biological activity of the protein model was confirmed semi-quantitatively and quantitatively through radial caseinolytic and chromogenic methods, respectively. There was a direct correlation between eGFP fluorescent intensity and SAK activity. The correlation and linearity of expression between the two genes were respectively confirmed with Pearson correlation and linear regression. Additionally, the precision, limit of detection (LOD), and limit of quantification (LOQ) were determined. The expression of eGFP and SAK was stable during four freeze–thaw cycles. In addition, the developed protocol showed that the transformants can be inoculated directly to the culture, saving time and reducing the error-prone step of colony picking. Conclusion The developed system is applicable for rapid screening of high-expressing colonies in most research laboratories. This system can be investigated for other recombinant proteins expressed in E. coli with a potential capability for automation and use at larger scales.


2020 ◽  
Vol 8 (7) ◽  
pp. 1030
Author(s):  
Cui-Cui Miao ◽  
Lin-Li Han ◽  
Yan-Bing Lu ◽  
Hong Feng

Bacillus subtilis is an ideal host for secretion and expression of foreign proteins. The promoter is one of the most important elements to facilitate the high-level production of recombinant protein. To expand the repertoire of strong promoters for biotechnological applications in Bacillus species, 14 highly transcribed genes based on transcriptome profiling of B. pumilus BA06 were selected and evaluated for their promoter strength in B. subtilis. Consequently, a strong promoter P2069 was obtained, which could drive the genes encoding alkaline protease (aprE) and green fluorescent protein (GFP) to express more efficiency by an increase of 3.65-fold and 18.40-fold in comparison with the control promoter (PaprE), respectively. Further, promoter engineering was applied to P2069, leading to a mutation promoter (P2069M) that could increase GFP expression by 3.67-fold over the wild-type promoter (P2069). Moreover, the IPTG-inducible expression systems were constructed using the lac operon based on the strong promoters of P2069 and P2069M, which could work well both in B. subtilis and B. pumilus. In this study, highly efficient expression system for Bacillus was constructed based on transcriptome data and promoter engineering, which provide not only a new option for recombinant expression in B. subtilis, but also novel genetic tool for B. pumilus.


2012 ◽  
Vol 78 (16) ◽  
pp. 5831-5838 ◽  
Author(s):  
Yun Zhang ◽  
Xiuling Shang ◽  
Shujuan Lai ◽  
Guoqiang Zhang ◽  
Yong Liang ◽  
...  

ABSTRACTCorynebacterium glutamicumis currently used for the industrial production of a variety of biological materials. Many available inducible expression systems in this species uselac-derived promoters fromEscherichia colithat exhibit much lower levels of inducible expression and leaky basal expression. We developed an arabinose-inducible expression system that contains thel-arabinose regulator AraC, thePBADpromoter from thearaBADoperon, and thel-arabinose transporter AraE, all of which are derived fromE. coli. The level of induciblePBAD-based expression could be modulated over a wide concentration range from 0.001 to 0.4%l-arabinose. This system tightly controlled the expression of the uracil phosphoribosyltransferase without leaky expression. When the gene encoding green fluorescent protein (GFP) was under the control ofPBADpromoter, flow cytometry analysis showed that GFP was expressed in a highly homogeneous profile throughout the cell population. In contrast to the case inE. coli,PBADinduction was not significantly affected in the presence of different carbon sources inC. glutamicum, which makes it useful in fermentation applications. We used this system to regulate the expression of theodhIgene fromC. glutamicum, which encodes an inhibitor of α-oxoglutarate dehydrogenase, resulting in high levels of glutamate production (up to 13.7 mM) under biotin nonlimiting conditions. This system provides an efficient tool available for molecular biology and metabolic engineering ofC. glutamicum.


2020 ◽  
Author(s):  
Ryo Sato ◽  
Kosuke Minamihata ◽  
Ryutaro Ariyoshi ◽  
Hiromasa Taniguchi ◽  
Noriho Kamiya

AbstractMicrobial transglutaminase from Streptomyces mobaraensis (MTG) has been widely used in food industry and also in research and medical applications, since it can site-specifically modify proteins by the cross-linking reaction of glutamine residue and the primary amino group. The recombinant expression system of MTG in E. coli provides better accessibility for the researchers and thus can promote further utilization of MTG. Herein, we report production of active and soluble MTG in E. coli by using a chimeric protein of tobacco etch virus (TEV) protease and MTG zymogen. A chimera of TEV protease and MTG zymogen with native propeptide resulted in active MTG contaminated with cleaved propeptide due to the strong interaction between the propeptide and catalytic domain of MTG. Introduction of mutations of K9R and Y11A to the propeptide facilitated dissociation of the cleaved propeptide from the catalytic domain of MTG and active MTG without any contamination of the propeptide was obtained. The specific activity of the active MTG was 22.7±2.6 U/mg. The successful expression and purification of active MTG by using the chimera protein of TEV protease and MTG zymogen with mutations in the propeptide can advance the use of MTG and the researches using MTG mediated cross-linking reactions.


Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1325 ◽  
Author(s):  
Ke Yue ◽  
Tran Nam Trung ◽  
Yiyong Zhu ◽  
Ralf Kaldenhoff ◽  
Lei Kai

Aquaporins are important and well-studied water channel membrane proteins. However, being membrane proteins, sample preparation for functional analysis is tedious and time-consuming. In this paper, we report a new approach for the co-translational insertion of two aquaporins from Escherichia coli and Nicotiana tabacum using the CFPS system. This was done in the presence of liposomes with a modified procedure to form homogenous proteo-liposomes suitable for functional analysis of water permeability using stopped-flow spectrophotometry. Two model aquaporins, AqpZ and NtPIP2;1, were successfully incorporated into the liposome in their active forms. Shifted green fluorescent protein was fused to the C-terminal part of AqpZ to monitor its insertion and status in the lipid environment. This new fast approach offers a fast and straightforward method for the functional analysis of aquaporins in both prokaryotic and eukaryotic organisms.


2006 ◽  
Vol 14 (21) ◽  
pp. 9815 ◽  
Author(s):  
Alberto Diaspro ◽  
Silke Krol ◽  
Barbara Campanini ◽  
Fabio Cannone ◽  
Giuseppe Chirico

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 632
Author(s):  
Yingyun Cai ◽  
Shuiqing Yu ◽  
Ying Fang ◽  
Laura Bollinger ◽  
Yanhua Li ◽  
...  

Simian hemorrhagic fever virus (SHFV) causes acute, lethal disease in macaques. We developed a single-plasmid cDNA-launch infectious clone of SHFV (rSHFV) and modified the clone to rescue an enhanced green fluorescent protein-expressing rSHFV-eGFP that can be used for rapid and quantitative detection of infection. SHFV has a narrow cell tropism in vitro, with only the grivet MA-104 cell line and a few other grivet cell lines being susceptible to virion entry and permissive to infection. Using rSHFV-eGFP, we demonstrate that one cricetid rodent cell line and three ape cell lines also fully support SHFV replication, whereas 55 human cell lines, 11 bat cell lines, and three rodent cells do not. Interestingly, some human and other mammalian cell lines apparently resistant to SHFV infection are permissive after transfection with the rSHFV-eGFP cDNA-launch plasmid. To further demonstrate the investigative potential of the infectious clone system, we introduced stop codons into eight viral open reading frames (ORFs). This approach suggested that at least one ORF, ORF 2b’, is dispensable for SHFV in vitro replication. Our proof-of-principle experiments indicated that rSHFV-eGFP is a useful tool for illuminating the understudied molecular biology of SHFV.


2011 ◽  
Vol 55 (5) ◽  
pp. 2438-2441 ◽  
Author(s):  
Zeynep Baharoglu ◽  
Didier Mazel

ABSTRACTAntibiotic resistance development has been linked to the bacterial SOS stress response. InEscherichia coli, fluoroquinolones are known to induce SOS, whereas other antibiotics, such as aminoglycosides, tetracycline, and chloramphenicol, do not. Here we address whether various antibiotics induce SOS inVibrio cholerae. Reporter green fluorescent protein (GFP) fusions were used to measure the response of SOS-regulated promoters to subinhibitory concentrations of antibiotics. We show that unlike the situation withE. coli, all these antibiotics induce SOS inV. cholerae.


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