Novel Antioxidant Protein Hydrolysates from Mung Bean (Vigna radiate): Structural Elucidation, Antioxidant Activity, and Molecular Docking Study

Mung bean (Vigna radiate) is nutritious and rich in protein (19.5–33.1%). However, there are few studies on mung bean protein active peptides. This study aimed to prepare antioxidant peptides from mung bean (V. radiate) protein hydrolysates (MBPHs) and further purify them to perform structural elucidation. Results showed that MBPHs protected HepG2 cells against H2O2-induced oxidative damage via enhancing SOD activity to inhibit the ROS and MDA content. To analyze the best antioxidant component, the hydrolysates were subsequently purified, and it was found that fraction F6 exhibited the strongest antioxidant activity among all fractions. Eight peptides from F6 were identified by UPLC–Q-TOF–MS/MS as Cys-Val-Val-Gly-Phe-His, Arg-Pro-Lys-Pro-Pro-His, Leu-Ala-Ala-Cys-Gly-Glu-Phe-His, Ala-Ser-Phe-Ala-Ser-Met-Pro-His, Gly-Asn-Trp-Gly-Pro-Leu, Gln-Pro-Ala-Asn-Val-Phe, Ala-Pro-Ala-Pro-Ile-Tyr, and Ala-Arg-Phe-Pro-Ala. Molecular docking revealed that the antioxidant activity resulted from the interaction between the peptide and the free radical by forming electrostatic interactions, hydrophobic interactions, and hydrogen bonds. Thus, mung bean (V. radiate) protein hydrolysates could be applied as a promising source of antioxidant peptides for nutraceutical applications.