DNAK DNAJ SUPPLEMENTATION IMPROVES THE PERIPLASMIC PRODUCTION OF HUMAN GRANULOCYTE-COLONY-STIMULATING FACTOR IN ESCHERICHIA-COLI/

Human granulocyte-colony stimulating factor (hG-CSF) can be efficientl y synthesized in E. coli as a fusion to a quimeric signal peptide, but this fusion is only partially exported to the periplasm. We have stud ied the effects of supplementing the host content in chaperonins on th e secretion of prehG-CSF in E. coli. We have found that the DnaK/DnaJ chaperonin system improves the secretion of this recombinant protein. This improvement correlates with an increase in the solubility of the precursor. Only a small fraction of the mature protein is released fro m the periplasm by an osmotic shock. (C) Academic Press, Inc.