ABSTRACT
To increase the amount of extracellular protein, a new series of secretion vectors pEAP82-l, pEAP82-2, and pEAP82-3 were constructed. The modified DNA fragment of the Fc structural gene was ligated with the large Cla 1-HindUl fragament of secretion vector pEAP8. A secretion vector, pEAP84 that contained a unique restriction site (Bgl II) at the 3' end of the penicillinase gene to allow production of a fused protein, and the Ex-kil region to make the outer membrane permeable, was constructed from pEAP82-l. A recombinant plasmid p84h06, which contained a synthetic gene for the human calcitonin, with a cyanogen bromide cleavage site at the junction site of the fused protein, was constructed and introduced into E coli. The secretion system showed several advantage for production of the peptide products; the penicillinase-fused product affords protection of the desired peptide from the enzymatic degradation.
