Introduction of Enterostatin (VPDPR) and a Related Sequence into Soybean Proglycinin A_1aB_1b Subunit by Site-directed Mutagenesis

Abstract

  Enterostatin (VPDPR), having anoretic and hypocholesterolemic activities, and its homologue LPYPR, a hypocholesterolemic peptide found in the glycinin A₅A₄B₃ subunit, were introduced into the corresponding site (TNGPQ) of the proglycinin A_1aB_1b subunit by site-directed mutagenesis. Modified proglycinins were expressed in E. coli and recovered from the insoluble fraction. VPDPR and LPYPR were released by the action of chymotrypsin and trypsin as expected. The overall yields of purified VPDPR and LPYPR were 40% and 62%, respectively.