Fig. 1

Chaperone assisted expression of soluble rGST-COE (a) and rGST-S1D (b). Chaperone proteins were induced at 37 °C by adding L-arabinose (0.5 mg/ml) or tetracycline (10 ng/ml) prior to the expression of recombinant proteins. Target proteins were induced by adding 0.1 mM IPTG at 15 °C for 24 h. Soluble (S) and insoluble (I) fractions were analyzed by SDS-PAGE. The protein bands for rGST-COE, rGST-S1D and chaperone proteins are indicated on the right side of the gel. Lanes: control, no chaperone; +TF, co-expression with trigger factor; +Gro, co-expression with GroEL-GroES complex; +G-KJE: co-expression with DnaKJE/GroEL-GroES complex