High-level expression of maize C4-type phosphoenolpyruvate carboxylase in Escherichia coli and its rapid purification

Maize C4-type phosphoenolpyruvate carboxylase (PEPC) was expressed in E. coli with the pET32 system. The expressed fusion PEPC was active and its amount comprised more than 10% of total soluble protein. The specific activity increased by about 45-fold, compared with our previous system [S. Yanagisawa and K. Izui, Agric. Biol. Chem., 54, 241-243 (1990)]. The fusion PEPC was rapidly purified with His bind metal chelation resin, showing a single band on SDS-PAGE. Moreover, the tag domain fused at the N-terminus did not have any effect on catalytic and regulatory properties of PEPC.