Biological activity evaluation and identification of different molecular weight peptides from wheat germ albumin
Shuangqi Tian, Fan‐hao Meng, Ke Du, Yanyan Chen
Abstract
The hydrolyzate of wheat germ albumin (WGA) has high biological activity. Under the action of proteases, WGA can release bioactive peptides such as antioxidant, antihypertensive, anti fatigue, antibacterial, etc. Ultrafiltration was used to separate different molecular weight peptides from WGA. The effects of proteases on hydrolysis of WGA and biological activities of different molecular weight peptides were comparatively studied and identified target bioactive peptides. When WGA was hydrolyzed by the enzymatic hydrolysis with papain, alcalase, acid protease, and neutral protease, the results showed that papain had the highest DPPH• scavenging rate. The scavenging rate of O2− radical for peptides with MW (<3 KDa) was higher than that of the other two components (WGA and >3 KDa), with an IC50 of 4.59 mg/mL, and its reducing power was significantly higher than that of WGA and MW (>3 KDa). The speculated identification results showed the screened amino acid (AA) sequences (<3 KDa), which mainly consisted of four types: NIYLNFDALHGDKEHGGVR, TGGDGGPGKPTT, DVFWIPRFFVQ, and EEEDKNDKWHRVE. The molecular weight of the dominant AA sequence was concentrated between 1000 and 2200 Da, and almost all functional peptides had high biological activity AA, such as His, Leu, Cys, Lys, and Tyr.