我们在此报告了一项关于抗氧化肽的研究，该肽显示出减轻心肌缺血再灌注损伤（MI/RI）的潜力。通过超滤和Sephadex G-15凝胶过滤获得的牦牛皮明胶组分Ac（YSG-Ac）具有良好的营养成分、高发泡能力和稳定性以及抗胃肠消化能力。 LC-MS/MS分析表明YSG-Ac含有26个肽段，序列长度为8至12个氨基酸。在线筛选表明，YSG-Ac 的抗氧化能力主要归因于疏水性和抗氧化氨基酸的存在。在体外，我们的结果证明了 YSG-Ac 通过有效修复 H2O2 诱导的 H9c2 细胞氧化损伤来发挥 MI/RI 保护作用，这是通过抑制丙二醛 (MDA) 水平、增加谷胱甘肽过氧化物酶 (GSH-pX) 和超氧化物来实现的歧化酶（SOD）活性。在体内，我们的结果进一步证实了 YSG-Ac 在小鼠 MI/RI 模型中缩小心肌梗塞面积、降低 MDA 水平、增加 SOD 活性和降低乳酸脱氢酶 (LDH) 含量的有效性。分子对接分析表明，PGADGQPGAK与黄嘌呤脱氢酶（XDH）和GAAGTPTGPIGS与肿瘤坏死因子-α（TNF-α）表现出较强的结合能力，其他相关靶点也对YSG-Ac表现出一定的结合能力。这表明 YSG-Ac 可以通过多个靶点和途径调节 MI/RI。总体而言，我们的研究结果凸显了 YSG-Ac 作为具有抗氧化和 MI/RI 保护特性的功能性食品成分的潜力。

We herein report a study on the antioxidant peptides that show potential in alleviating myocardial ischemia reperfusion injury (MI/RI). Yak skin gelatin fraction Ac (YSG-Ac), obtained through ultrafiltration and gel filtration with Sephadex G-15, exhibits a favorable nutrient composition, high foaming capacity and stability, and resistance against gastrointestinal digestion. LC-MS/MS analysis reveals that YSG-Ac contains 26 peptide segments with sequence lengths of 8 to 12 amino acids. Online screening suggests that the antioxidant capacity of YSG-Ac is mainly attributed to the presence of hydrophobic and antioxidant amino acids. In vitro, our results demonstrate the MI/RI protective effects of YSG-Ac by effectively repairing H2O2-induced oxidative damage in H9c2 cells, which is achieved by inhibiting malondialdehyde (MDA) levels, and increasing glutathione peroxidase (GSH-pX) and superoxide dismutase (SOD) activity. In vivo, our results further confirm the effectiveness of YSG-Ac in narrowing the area of myocardial infarction, decreasing MDA levels, increasing SOD activity, and reducing the content of lactate dehydrogenase (LDH) in a mouse MI/RI model. Molecular docking analysis indicates that PGADGQPGAK with xanthine dehydrogenase (XDH) and GAAGPTGPIGS with tumor necrosis factor-alpha (TNF-α) exhibit strong bonding capability, and other related targets also show certain binding ability toward YSG-Ac. This suggests that YSG-Ac can regulate MI/RI through multiple targets and pathways. Overall, our findings highlight the potential of YSG-Ac as a functional food ingredient with antioxidant and MI/RI protective characteristics.