Synthesis of a gene encoding bovine substance P precursors and its expression in Escherichia coli

Using an efficient Escherichia coli expression system, we have been able to obtain the precursor of substance P, alpha-preprotachykinin (alpha PPT). The alpha PPT protein is produced in E. coli as a fusion to beta-galactosidase, and accumulates in the cytoplasm as insoluble inclusion bodies. We also produced protachykinin (alpha PT), i.e., alpha PPT without a signal peptide. Further purification and characterization of the alpha PPT and alpha PT polypeptides strongly suggest that fully purified products can be obtained using our procedures.