Identification and Characterization of Novel ACE Inhibitory and Antioxidant Peptides from Sardina pilchardus Hydrolysate

Mingyang Shao; Haixing Wu; Bohui Wang; Xuan Zhang; Xia Gao; Mengqi Jiang; Ruiheng Su; Xuanri Shen

doi:10.3390/foods12112216

Identification and Characterization of Novel ACE Inhibitory and Antioxidant Peptides from Sardina pilchardus Hydrolysate

Foods. 2023 May 31;12(11):2216. doi: 10.3390/foods12112216.

Authors

Mingyang Shao^{1

2

3}, Haixing Wu^{1

2

3}, Bohui Wang^{1

2

3}, Xuan Zhang^{1

2

3}, Xia Gao^{1

2

3}, Mengqi Jiang^{1

2

3}, Ruiheng Su^{1

2

3}, Xuanri Shen^{1

2

3}

Affiliations

¹ School of Food Science and Engineering, Hainan University, Haikou 570228, China.
² Key Laboratory of Food Nutrition, Functional Food of Hainan Province, Haikou 570228, China.
³ Hainan Engineering Research Center, Aquatic Resources Efficient Utilization in South China Sea, Hainan University, Haikou 570228, China.

Abstract

Sardina pilchardus is a valuable source of bioactive peptides with potential applications in functional foods. In this study, we investigated the angiotensin-converting enzyme (ACE) inhibitory activity of Sardina pilchardus protein hydrolysate (SPH) produced using dispase and alkaline protease. Our results showed that the low molecular mass fractions (<3 kDa) obtained through ultrafiltration exhibited more effective ACE inhibition, as indicated by screening with ACE inhibitory activity. We further identified the low molecular mass fractions (<3 kDa) using an LC-MS/MS rapid screening strategy. A total of 37 peptides with potential ACE inhibitory activity were identified based on high biological activity scores, non-toxicity, good solubility, and novelty. Molecular docking was used to screen for peptides with ACE inhibitory activity, resulting in the identification of 11 peptides with higher -CDOCKER ENERGY and -CDOCKER INTERACTION ENERGY scores than lisinopril. The sequences FIGR, FILR, FQRL, FRAL, KFL, and KLF were obtained by synthesizing and validating these 11 peptides in vitro, all of which had ACE inhibitory activity, as well as zinc-chelating capacity. All six peptides were found to bind to the three active pockets (S1, S2, and S1') of ACE during molecular docking, indicating that their inhibition patterns were competitive. Further analysis of the structural characteristics of these peptides indicated that all six peptides contain phenylalanine, which suggests that they may possess antioxidant activities. After experimental verification, it was found that all six of these peptides have antioxidant activities, and we also found that the SPH and ultrafiltration fractions of SPH had antioxidant activities. These findings suggest that Sardina pilchardus may be a potential source of natural antioxidants and ACE inhibitors for the development of functional foods, and using LC-MS/MS in combination with an online database and molecular docking represents a promising, effective, and accurate approach for the discovery of novel ACE inhibitory peptides.

Keywords: ACE inhibitory activity; LC-MS/MS; Sardina pilchardus; antioxidant activity; molecular docking.

Grants and funding

This work was supported by Haikou Science and Technology Program (Number: 2020-052).