Antioxidative Activity of Peptides Prepared by Enzymatic Hydrolysis of Egg-White Albumin

Abstract

The antioxidative activity of protease hydrolyzates of four proteins against linoleic acid was investigated in an aqueous system at pH 7.0. Eight kinds of protease were used. The egg-white albumin hydrolyzate prepared with Amano S (from Bacillus subtilis) had the strongest antioxidative activity. From this hydrolyzate, three antioxidative peptides were purified by Sephadex G-25 gel filtration, CM Sephadex C-25 column chromatography, and then HPLC on an octadeceyl column. The amino acid sequences of the peptides were Ala-His-Lys (P1), Val-His-His (P2), and Val-His-His-Ala-Asn-Glu-Asn (P3). The antioxidative activity of P1 was the strongest, and the activities of P2 and P3 were about half that of P1. A mixture of Fe2+and egg-white albumin hydrolyzate was separated by Sephadex G-25 gel filtration, and the recovery of Fe2+was measured. Most of the bound iron was eluted in the fractions corresponding to the peak of the antioxidative activity. This suggests that the antioxidative activity was based on the chelating activity of the peptides. © 1991, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.