The relative importance of intracellular proteolysis and transport on the yield of the periplasmic enzyme penicillin amidase in Escherichia coli

Intracellular proteolysis is an important mechanism for regulating the leve l of the periplasmic enzyme penicillin amidase in Escherichia coli. Evidenc e is presented that the active enzyme is localized in the periplasmic space and maturation of pro-enzyme occurs during transport through the cytoplasm ic membrane or rapidly after its entrance in the periplasm. The rate consta nts of the transport through cytoplasmic membrane and of the intracellular proteolysis were estimated to be 0.01 h and 0.5 h, respectively. This indic ates that more than 90% of the synthesized pre-pro-enzyme is lost by intrac ellular proteolysis occurring in the cytoplasm. (C) 2000 Elsevier Science I nc. All rights reserved.