Department of Food Science and Engineering , Jinan University , Huangpu Road 601, Guangzhou , Guangdong 510632 , China.
College of Light Industry , Sichuan University , Chengdu , Sichuan 610065 , China.
J Agric Food Chem. 2019 Jul 10;67(27):7650-7659. doi: 10.1021/acs.jafc.9b01115. Epub 2019 Jun 26.
Neutrase-hydrolysates hydrolyzed from mulberry leaf proteins were separated by ion exchange chromatography, gel filtration chromatography, and semipreparative reverse-phase HPLC. Purified fractions were analyzed for their radical scavenging activity, hemolysis inhibition ability, and cellular antioxidant activity (CAA). Three new antioxidant peptides, P1 (SVL, 317 Da), P2 (EAVQ, 445 Da), and P3 (RDY, 452 Da), were obtained from the most active HPLC fraction (R1) and identified using UPLC-QTOF-MS. These three peptides were then synthesized, and their antioxidant activities were analyzed. P1 and P2 had no ability to inhibit hemolysis of erythrocytes but did show antioxidant activity on HepG2 cells. P3 showed the highest hemolysis inhibition ability (92%) and CAA value (2204 μM QE/100 g peptide). The Tyr residues at the C-terminal region play an important role in the antioxidant activity in P3. Thus, the natural peptide R1 and synthesized P3 could be used as antioxidants and might be promising components of functional foods.
从桑叶蛋白中酶解得到的中性蛋白酶水解产物，经离子交换色谱、凝胶过滤色谱和半制备反相高效液相色谱分离。对纯化的各馏分进行自由基清除活性、溶血抑制能力和细胞抗氧化活性（CAA）分析。从活性最高的 HPLC 馏分（R1）中获得 3 种新的抗氧化肽 P1（SVL，317 Da）、P2（EAVQ，445 Da）和 P3（RDY，452 Da），并采用 UPLC-QTOF-MS 进行鉴定。然后对这 3 种肽进行了合成，并分析了它们的抗氧化活性。P1 和 P2 没有抑制红细胞溶血的能力，但对 HepG2 细胞具有抗氧化活性。P3 显示出最高的溶血抑制能力（92%）和 CAA 值（2204 μM QE/100 g 肽）。C 末端区域的 Tyr 残基对 P3 的抗氧化活性起着重要作用。因此，天然肽 R1 和合成肽 P3 可用作抗氧化剂，可能是功能性食品有前途的成分。
