Overview

The Chaperone Plasmid Set consists of five different plasmids, each of which is designed to express multiple molecular chaperones that function as a "chaperone team" to enable protein folding. Co-expression of a target protein with one of these chaperone teams increases the recovery of soluble proteins. Each plasmid carries an origin of replication derived from pACYC and a Cmr gene, which allows use with E. coli expression systems utilizing ColE1-type plasmids containing an ampicillin resistance gene as a marker. The chaperone genes are situated downstream of an araB or Pzt-1 (tet) promoter. Therefore, expression of target proteins and chaperones can be induced individually if the target gene is placed under the control of other promoters (e.g. lac). These plasmids also contain the necessary regulator (araC or tetr) for each promoter.

Use this set to perform a two step method to construct target/chaperone co-expression systems: In the first step prepare an E. coli host transformed with only the chaperone plasmid. The second step is to prepare competent cells from this new strain and transform this strain with a plasmid expressing the target protein.

Applications

• Correct in vivo folding of expressed recombinant proteins in E. coli
• Reduction of insoluble protein during expression