Design and production of genetically modified soybean protein with anti-hypertensive activity by incorporating potent analogue of ovokinin(2-7)

The potent anti-hypertensive peptide, RPLKPW, has been designed based on th e structure of ovokinin(2-7), The sequence encoding this peptide was introd uced into three homologous sites in the gene for soybean beta -conglycinin alpha' subunit, The native alpha' subunit as well as the modified, RPLKPW-c ontaining alpha' subunit were expressed in Escherichia coli, recovered from the soluble fraction and then purified by ion-exchange chromatography. The RPLKPW peptide was released from recombinant RPLKPW-containing alpha' subu nit after in vitro digestion by trypsin and chymotrypsin, Moreover, the und igested RPLKPW-containing alpha' subunit given orally at a dose of 10 mg/kg exerted an anti-hypertensive effect in spontaneously hypertensive rats, un like the native alpha' subunit, These results provide evidence for the firs t time that a physiologically active peptide introduced into a food protein by site-directed mutagenesis could practically function in vivo even at a low dose. (C) 2001 Published by Elsevier Science B.V. on behalf of the Fede ration of European Biochemical Societies.