title: Expression and excretion of human pancreatic secretory trypsin inhibitor in lipoprotein-deletion mutant of Escherichia coli.
abstract: We constructed a gene coding for the 56-amino acid human pancreatic secretory trypsin inhibitor (PSTI), and ligated it on a plasmid downstream from the trp promoter and the signal peptide sequence of alkaline phosphatase. The resulting plasmid was transfected into a lipoprotein deletion mutant (Escherichia coli JE5505) and the plasmid-carrying cells were induced with 3-indoleacrylic acid. A considerable amount (50 micrograms/ml culture) of the mature PSTI protein was detected in the culture supernatant. The excreted PSTI was identical to the natural PSTI protein with respect to the trypsin-inhibiting activity, the N-terminal and the C-terminal amino acid sequences and the amino acid composition.
mesh_terms: D001483:Base Sequence; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D008074:Lipoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010179:Pancreas; D010957:Plasmids; D011401:Promoter Regions, Genetic; D014361:Trypsin Inhibitors / Q000235:genetics* / Q000652:urine
chemical_list: D008074:Lipoproteins; D014361:Trypsin Inhibitors