Expression and Purification of serine protease inhibitor, OH-TCI, in Escherichia coli as a thioredoxin fusion protein

摘要

The OH-TCI was the first report of Kunitz/BPTI serine proteinase inhibitor from snake venom with strong inhibitory activity against trypsin and chymotrypsm. Thus it is theoretically attractive in ameliorating the effects of acute pancreatitis and reducing allogeneic blood product transfusion during cardiac surgery. To accomplish preclinical evaluation with OH-TCI, large-scale production of OH-TCI is produced in Escherichia coli. The optimized OH-TCI codons were cloned into pET32a(+). OH-TCI expressed as Trx tag is solubility as fusion bodies. The amount of the purified Trx-OH-TCI from 1 liter culture was roughly 200 mg. The inhibitor constants (Ki) of Trx-OH-TCI, similar to the native OH-TCI, were 2.67×10~(-7) and 3.60×10~(-7) M M for trypsin and chymotrypsin, respectively.