E. coli Enzyme Expression System

Creative Enzymes is an industrial biotechnology company which has been providing and optimizing customized services for expression of recombinant enzymes in multiple systems. We have tested different hosts systems and gained extensive experiences through years of practice. The knowledge of various expression hosts enables case-specific expression for each enzyme, where the expression vector and host strain are selected from our versatile collection for the goal of the highest yield at an acceptable cost level. Various purification tags are also available in expression constructs when required. Creative Enzymes is equipped with the most advanced operation facilities, and the expert team is able to follow up with downstream processing and purification.

Escherichia coli is the most commonly used organism for the production of recombinant enzymes serving for both laboratory investigations and initial development in commercial activities because it is easy, fast, and inexpensive to cultivate. Besides, its vector systems have been well developed. So it is no surprise that E. coli expression system accounts for the largest share of all systems in industrial and pharmaceutical protein production. As the dominating bacterial expression system, it also serves as a useful benchmark for comparison among various expression platforms. E. coli expression system is the basis for efforts in enzyme engineering and high-throughput structural analysis. This system also plays a key role in the functional expression of non-glycosylated proteins. Other benefits of using the system are that the genome of E. coli can be quickly and precisely modified with ease, promoter control is not difficult, and the plasmid copy number can be readily altered. Furthermore, E. coli system also plays a critical role in the change of metabolic carbon flow, the avoidance of incorporation of amino acid analogs, the configuration of intracellular disulfide bonds, and reproducible performance with computer control. E. coli can accumulate recombinant proteins up to eighty percent of its dry weight and survives varieties of environmental conditions, which makes it ideal for mass production.

However, E. coli system also has some disadvantages. For example, owning to the formation of acetate, high cell densities can lead to cell toxicity. This condition can be avoided by controlling the level of oxygen. Additionally, proteins which are produced as inclusion bodies are often inactive, insoluble, and subject to refolding. Furthermore, the proteins produced by this system with many disulfide bonds are extremely difficult to refold. Likewise, the E. coli system are usually limited to production f unglycosylated proteins. Besides, a disadvantage for therapeutic use of produced recombinant enzymes in E. coli is the accumulation of lipopolysaccharide (LPS), namely endotoxins, which are pyrogenic in humans and other mammals. Proteins for this application must be purified in a second step to become endotoxin-free.

Therefore, in order to overcome these drawbacks of the E. coli system, Creative Enzymes has developed multiple methods to ameliorate its process, such as using different promoters, using different host strains, co-expression of chaperones or foldases, lowering the temperature, and secretion of proteins into the periplasmic space or the medium. Besides, the problem of acetate production and cell toxicity can be fixed by feeding glucose exponentially, and keeping the specific growth rate below that which brings on acetate production. For most service request, we recommend the E. coli system as the first try for its low costs and robust fermentation conditions. Generally, the E. coli expression service of Creative Enzymes offers a customer-oriented solution to help researchers and companies to successfully produce their recombinant enzymes. Overall, Creative Enzymes can provide customers with rapid and efficient enzyme expression and production, as well as complete tailor-made services of producing a unique enzyme of interest.