[Cloning, expression and purification of the chaperonin GroESL in Escherichia coli].

The DNA fragment encoding the molecular chaperion GroESL was subcloned into high-expression vector pKC220, and the GroESL were high expressed in the E. coli strain harboring the recombinant plasmid by high temperature induction. The amount of the expressed GroEL and GroES protein were about 40% and 15% of the total cellular proteins, respectively. These two subunits were both purified from E. coli by (NH4)2SO4 salt out DEAE-52 chromography and Sephadex G-50 chromography.