E. coli expression system has been the first choice for mass production of many recombinant proteins with low production cost. One of the fundamental reasons why E. coli is so widely used is the availability of various strong inducible promoters. Thermoregulated expression systems have been successfully used to produce many recombinant proteins and peptides because they rely on strong and finely regulated promoters and avoid the use of special media, toxic or expensive chemical inducers.
A heat-inducible expression system based on pL and/or pR phage lambda promoters is now available at Creative BioMart. The system is regulated by the thermolabile cI857 repressor and it has been widely applied in the field of recombinant protein production.
The expression system of λpL/pR-cI857 shows other important advantages. A single copy of the ci857 gene produces enough repressors to completely inhibit the activity of pL or pR promoter, even if the promoter exists in a multicopy plasmid. The heat induction system can be used for almost any E.coli strain, or even for other gram-negative bacteria, such as euvenis and sarrella. In addition, according to protein, bacterial strain and culture conditions, up to 30% of recombinant proteins can be produced by using the expression system.
The principle of the temperature regulation expression system is very simple. The gene of interest is inserted into different vectors containing strong major left (pL) and/or right (pR) promoters. The expression of the target gene can be detected by phage λ. The heat-labile cI857 repressor of the mutant is effectively regulated. Gene expression is inhibited at temperatures below 37 degrees (usually in the range of 28-32 degrees), while the transcription of host RNA polymerase occurs after the inactivation of the mutant repressor by increasing the temperature above 37 degrees.
Figure 1. Representation of the pL/pR promoters controlled by the cI857 repressor. (Valdez-Cruz, 2010)
We offer a variety of flexible service packages for you to choose from.
| Service Name | Service Description |
| Preparation of vector backbone |
|
| Preparation of target DNA |
|
| Subclone construction |
|
| Protein expression |
|
| Scale up and protein purification |
|
Client only needs to provide the target sequence and requirements. We will be responsible for the steps including codon evaluation, expression vector design, induced expression, expression condition optimization, protein product detection, and large-scale production.
We can also build an expression vector for you. Our library contains hundreds of compatible plasmid vector skeletons, which can build multiple vector candidates according to your needs.
Customers who need our assistance are more than welcome to contact us or submit an online inquiry. Our professional team will provide you with detailed guidance and solution ASAP.
Reference
1. Valdez-Cruz, N.A., Caspeta, L., Pérez, N., Ramírez, O., & Trujillo-Roldán, M. (2010). Production of recombinant proteins in E. coli by the heat-inducible expression system based on the phage lambda pL and/or pR promoters. Microbial Cell Factories, 9, 18 - 18.
