Production of bovine-pancreatic-trypsin-inhibitor homologues in Escherichia coli and their characterization
Chesshyre, J.A.; Kraunsoe, J.A.; Lowe, G.
Biotechnology and Applied Biochemistry 22(3): 269-280
1995
ISSN/ISBN: 0885-4513 PMID: 8573289 Document Number: 450197
Biologically active bovine pancreatic trypsin inhibitor (BPTI) was produced in Escherichia coli using an OmpA leader-peptide fusion-protein system, and BPTI homologues were generated by cassette mutagenesis. Amino acids in the reactive loop of alpha-1-proteinase inhibitor (alpha-1-PI) were incorporated into the reactive loop of BPTI in a stepwise approach such that the contribution of individual amino acids could be assessed. The introduction of mutations into BPTI diminished the yield of heterologous protein relative to wild-type BPTI. However, for three BPTI homologues sufficient material was isolated to allow characterization of the proteins by electrospray MS and N-terminal peptide sequencing.