Clontech/Chaperone plasmid set/1 Set/3340

The Chaperone Plasmid Set consists offive different plasmids, each of which is designed to express multiple molecular chaperones that function together as a "chaperone team" to enable optimal protein expression andfolding and to reduce protein misfolding. Co-expression of a target protein with one of these five chaperoneplasmids increases the recovery of soluble protein and minimizes product loss as a result of insoluble protein. Each plasmid carries an origin of replication (ori)derived from pACYC and a chloramphenicol-resistance gene (Cm^r) gene, which allows theuseof E. coli expression systemscontaining ColE1-type plasmids that confer ampicillin resistance. The chaperone genes are situated downstream ofthe araB orPzt-1 (tet) promoters; as a result, expression of target proteins and chaperones can be individually induced if the target gene is placed under the control ofdifferent promoters (e.g., lac). These plasmids also contain the necessary regulator (araC or tet^r) for each promoter.

Compatible E. coli expression systems

1. The Chaperone Plasmid Setoffersa pACYC ori and Cm^r gene, allowing the useof E. coli expression systems that utilize colE1-type plasmidswithampicillin resistance. The Chaperone PlasmidSetcannot be used in combination with chloramphenicol-resistant E. coli host strains or expression plasmids that carry a chloramphenicol-resistance gene. For example, E. coli BL21(DE3), which is often used with pET and other systems, is a compatible host strain. However,E. coli BL21(DE3) pLysS and BL21(DE3) pLysE, both of which contain the pACYC replication origin and Cm^r gene-containing pLysS or pLysE plasmids, cannot be used with this system.
2. This product prescribes a two-step method to construct target protein/chaperone co-expression systems, the first step describing how to prepare an E. coli host transformed withjust the chaperone plasmid, and the second step describing how to prepare competent cells from the chaperone plasmid-containing strain and to transform this strain withthe target protein-containingplasmid.

Plasmids in the Chaperone Plasmid Set work well in combination withthe pCold Expression System Vectors.