Rapeseed protein hydrolysates: a source of HIV protease peptide inhibitors

Inhibitors of the human immunodeficiency virus (HIV) protease can be obtained from microbial and plant sources. The presence of inhibitors in protein hydrolysates obtained by treatment of rapeseed protein isolates with the food grade endoprotease alcalase was investigated. Inhibitory activity was determined by measuring growth of E. coli expressing the HIV protease. Hydrolysis of rapeseed protein with alcalase resulted in the generation of peptides that inhibited the HIV protease, which implies that those peptides can be absorbed from the medium by the cells in the inhibition assays. Two fractions rich in peptidic HIV protease inhibition were obtained by size exclusion chromatography. These results exemplify a new approach in the research of HIV protease inhibitors.