scholarly journals Overview of Bacterial and Yeast Systems for Protein Expression

Author(s):  
Maheswara Reddy Mallu ◽  
Siva Reddy Golamari ◽  
Sree Rama Chandra Karthik Kotikalapudi ◽  
Renuka Vemparala

Over the past decade the variety of hosts and vector systems for recombinant protein expression has increased dramatically. Researchers now select from among mammalian, insect, yeast, and prokaryotic hosts, and the number of vectors available for use in these organisms continues to grow. With the increased availability of cDNAs and protein coding sequencing information, it is certain that these and other, yet to be developed systems will be important in the future. Despite the development of eukaryotic systems, E. coli remains the most widely used host for recombinant protein expression. Optimization of recombinant protein expression in prokaryotic and eukaryotic host systems has been carried out by varying simple parameters such as expression vectors, host strains, media composition, and growth temperature. Recombinant gene expression in eukaryotic systems is often the only viable route to the large-scale production of authentic, post translationally modified proteins. It is becoming increasingly easy to find a suitable system to overexpress virtually any gene product, provided that it is properly engineered into an appropriate expression vector.

Author(s):  
N. Hemamalini ◽  
S. Ezhilmathi ◽  
A. Angela Mercy

Escherichia coli is the most extensively used organism in recombinant protein production. It has several advantages including a very short life cycle, ease of genetic manipulation and the well-known cell biology etc. which makes E. coli as the perfect host for recombinant protein expression. Despite many advantages, E. coli also have few disadvantages such as coupled transcription and translation and lack of eukaryotic post-translational modifications. These challenges can be overcome by adopting several strategies such as, using different E. coli expression vectors, changing the gene sequence without altering the functional domain, modified E. coli strain usage, changing the culture parameters and co-expression with a molecular chaperone. In this review, we present the level of strategies used to enhance the recombinant protein expression and its stability in E. coli.


1997 ◽  
Vol 77 (04) ◽  
pp. 755-759 ◽  
Author(s):  
Jianming Gu ◽  
Yue Liu ◽  
Lijun Xia ◽  
Haiying Wan ◽  
Peixia Li ◽  
...  

SummaryA murine monoclonal (mAb) SZ-51 specific for human P-selectin may be used for in vivo thrombus imaging and for the targeting of fibrinolytic agents to thrombi. In order to reduce the immunogenicity of the murine mAb SZ-51 in humans, we cloned and sequenced the cDNAs encoding the variable region of mAb SZ-51 in order to develop mouse/human chimeric reagents. The E. coli expression vector. pHENl-SZ51 Fab/Hu was constructed by fusing the variable regions of mAb SZ-51 with human IgG γICHI and Cκ genes. The constructs were introduced into E. coli HB2151 for expression of soluble chimeric Fab fragment. We also constructed two fusion products by joining the variable regions of mouse antibody to the appropriate constant regions of human Igγl and κ. These chimeras were cloned into two eukaryotic selectable expression vectors separately, which were then cotransfected into a non-Ig secreting murine myeloma line SP2/0 with lipofectin reagent. Six cell lines remained positive for Ig secretion. The highest producing cell line, which showed stable integration and expression at 5 mg/1 of culture, was selected for the large scale production of chimeric antibody. Immunoblotting analysis demonstrated that both of the chimeric antibodies (SZ51Fab/Hu, SZ51/Hu) in the culture supernatants, like the native mAb SZ-51, bind P-selectin. In addition, the whole chimeric antibody can compete for binding to activated platelets with murine SZ-51. Therefore, the SZ-51 chimeric antibody may be a potential agent for diagnosis and treatment of thrombotic diseases in the future.


2020 ◽  
Vol 27 (6) ◽  
pp. 529-537 ◽  
Author(s):  
Vibhor Mishra

The Baculovirus Expression Vector System (BEVS) is a workhorse for recombinant protein expression for over thirty-five years. Ever since it was first used to overexpress the human IFN-β protein, the system has been engineered and modified several times for quick and easy expression and scale-up of the recombinant proteins. Multiple gene assemblies performed on the baculovirus genome using synthetic biology methods lead to optimized overexpression of the multiprotein complexes. Nowadays, several commercially available BEVS platforms offer a variety of customizable features, and often it is confusing which one to choose for a novice user. This short review is intended to be a one-stop guide to the commercially available baculovirus technology for heterologous protein expression in the insect cells, which users can refer to choose from popular and desirable BEVS products or services.


2003 ◽  
Vol 84 (10) ◽  
pp. 2669-2678 ◽  
Author(s):  
Gorben P. Pijlman ◽  
Jessica E. van Schijndel ◽  
Just M. Vlak

Repeated baculovirus infections in cultured insect cells lead to the generation of defective interfering viruses (DIs), which accumulate at the expense of the intact helper virus and compromise heterologous protein expression. In particular, Autographa californica multicapsid nucleopolyhedovirus (AcMNPV) DIs are enriched in an origin of viral DNA replication (ori) not associated with the homologous regions (hrs). This non-hr ori is located within the coding sequence of the non-essential p94 gene. We investigated the effect of a deletion of the AcMNPV non-hr ori on the heterologous protein expression levels following serial passage in Sf21 insect cells. Using homologous ET recombination in E. coli, deletions within the p94 gene were made in a bacterial artificial chromosome (BAC) containing the entire AcMNPV genome (bacmid). All bacmids were equipped with an expression cassette containing the green fluorescent protein gene and a gene encoding the classical swine fever virus E2 glycoprotein (CSFV-E2). For the parental (intact) bacmid only, a strong accumulation of DIs with reiterated non-hr oris was observed. This was not observed for the mutants, indicating that removal of the non-hr ori enhanced the genetic stability of the viral genome upon passaging. However, for all passaged viruses it was found that the entire BAC vector including the expression cassette was spontaneously deleted from the viral genome, leading to a rapid decrease in GFP and CSFV-E2 production. The rationale for the (intrinsic) genetic instability of the BAC vector in insect cells and the implications with respect to large-scale production of proteins with bacmid-derived baculoviruses are discussed.


Sign in / Sign up

Export Citation Format

Share Document