A simple generic method for optimizing membrane protein overexpression in Escherichia coli is still lacking. We have studied the physiological response of the widely used "Walker strains" C41(DE3) and C43(DE3), which are derived from BL21(DE3), to membrane protein overexpression. For unknown reasons, overexpression of many membrane proteins in these strains is hardly toxic, often resulting in h...

We have investigated the over-production of seven membrane proteins in an Escherichia coli-bacteriophage T7 RNA polymerase expression system. In all seven cases, when expression of the target membrane protein was induced, most of the BL21(DE3) host cells died. Similar effects were also observed with expression vectors for ten globular proteins. Therefore, protein over-production in this express...

Mpro is one of the most important drug targets novel Coronavirus. In this study, a series potential compounds were obtained through virtual screening targeting Mpro. Using key protease (Mpro) SARS-COV-2 as lead target for has become hot topic in current virus research. plays role replication and transcription. Therefore, experimental strain Escherichia coli containing commonly used to inhibit d...

Abnormal production of interferon alpha (IFN-alpha) has been found in certain autoimmune diseases and can be also observed after prolonged therapy with IFN-alpha. IFN-alpha can contribute to the pathogenesis of allograft rejection in bone marrow transplants. Therefore, the development of IFN-alpha inhibitors as a soluble receptor protein may be valuable for the therapeutic control of these dise...

Phage contamination has become a major concern for industrial bacteria, such as Escherichia coli BL21(DE3), used in fermentation processes. Herein, we report CRISPR/Cas9 defense system-based strategy to precisely prey and degrade phage DNA decontaminate target phages. First, isolated novel from substrates with BL21(DE3) the host, named TR1. It showed typical podovirus morphology head diameter o...

BACKGROUND Eukaryotic DNA polymerase β (pol β), the polymerase thought to be responsible for DNA repair synthesis, has been extensively characterized in rats and humans. However, pol β has not been purified or enzymatically characterized from the model fish species Danio rerio (zebrafish). We used the in vitro/in vivo dual expression system plasmid, pIVEX, to express Danio rerio pol β (Danio po...

An overexpression system for squalene-hopene cyclase (SHC) was constructed by using the pET3a vector, which is responsible for high expression with help from the strong T7 promoter when incorporated into E. coli BL21(DE3). Site-directed mutagenesis experiments prove that two amino acid residues of tryptophan and aspartic acid inside the QW-motif 5 resided as active sites.

Human epidermal growth factor receptor (HER) family plays an important role in various types of cancers. As a result, antibodies against HER and the mechanism of antigen-antibody binding action are under active investigation. We previously constructed a single-chain variable fragment (ScFv) against HER2, i.e. anti-Her2 ScFv, for expressing in the Escherichia coli. In the present study, we repor...

Background and Aims: Q59L mutant of L-asparaginase enzyme from Escherichia coli (E. coli) has been introduced with lower side effects. This version of the enzyme might have potential applications in the treatment of leukemia patients. We utilized SHuffle T7 strain of E. coli, to produce the mutant enzyme in the presence of chaperone molecules. Materials and Methods: Q59LAsp gene was cloned in...