College of Food Sciences and Engineering, South China University of Technology, Guangzhou 510640, China.
School of Public Health, Guangdong Pharmaceutical University, Jianghai Avenue 283, Haizhu District, Guangzhou 510006, China.
Food Chem. 2024 Jan 15;431:137137. doi: 10.1016/j.foodchem.2023.137137. Epub 2023 Aug 12.
Earthworms are emerging sources of edible animal proteins. Earthworm extracts exhibit good in vivo antioxidant activity after oral administration. To better understand the antioxidant activity of earthworms, antioxidant peptides derived from earthworm proteins after gastrointestinal digestion were isolated and identified, and their structure-activity relationships were analysed in this research. Results showed that earthworm protein gastrointestinal digestion products exhibited good antioxidant activity, and 6030 peptide sequences were identified after separation using ion-exchange and gel-chromatography columns. Eleven peptides were screened using computer simulation activity scores, among which AFWYGLPCKL, WPWQMSLY, and GCFRYACGAFY showed the best antioxidant activities. Highest Occupied Molecular Orbital (HOMO) analysis indicated that N-H, O-H, and the peptide bond binding sites of serine and leucine were active sites of peptides AFWYGLPCKL, GCFRYACGAFY, and WPWQMSLY, respectively. This study provides a new understanding of substance basis of antioxidant activity in earthworms and contributes to application of earthworm proteins as antioxidants in health-foods.
蚯蚓是新兴的可食用动物蛋白质来源。蚯蚓提取物经口服后表现出良好的体内抗氧化活性。为了更好地理解蚯蚓的抗氧化活性，本研究从蚯蚓蛋白的胃肠道消化产物中分离并鉴定了抗氧化肽，并分析了它们的结构-活性关系。结果表明，蚯蚓蛋白的胃肠道消化产物具有良好的抗氧化活性，经离子交换和凝胶色谱柱分离后鉴定出 6030 条肽序列。通过计算机模拟活性评分筛选出 11 条肽，其中 AFWYGLPCKL、WPWQMSLY 和 GCFRYACGAFY 表现出最佳的抗氧化活性。最高占据分子轨道（HOMO）分析表明，肽 AFWYGLPCKL、GCFRYACGAFY 和 WPWQMSLY 的 N-H、O-H 和丝氨酸及亮氨酸的肽键结合位点分别是它们的活性位点。本研究为蚯蚓抗氧化活性的物质基础提供了新的认识，并有助于将蚯蚓蛋白作为抗氧化剂应用于保健食品。
