Expression vector promoting the synthesis and export of the human growth-hormone-releasing factor in Escherichia coli.

ABSTRACT

We have studied the synthesis, processing and export of human growth-hormone-releasing factor (hGRF) in Escherichia coli transformed with a plasmid constructed for the expression of hGRF as a hybrid protein. A DNA fragment containing the entire sequence of phosphate-binding protein gene (phoS) is fused to a modified hGRF-coding sequence (phoS-mhGRF). The hybrid protein, PhoS-mhGRF, was recovered in the supernatant fluid after spheroplasting treatment indicating correct export to the periplasmic space. Pulse-chase experiments demonstrated that the hybrid protein was similarly processed as the PhoS precursor.