Abstract The aims of this study included evaluation of copper-binding capacity (CBC) and amino acid composition of salmon by-product proteolysate and its peptide fractions, optimization of hydrolysis condition, and identification of copper-binding peptides from the proteolysate. The result was that under the ideal hydrolysis (Neutrase, temperature of 45 °C, pH 7, enzyme:substrate (E:S) proportion of 72.24 U/g protein and hydrolysis time of 8.02 h), the proteolysate had the indispensable amino acid content at approximately 38.7% and also displayed the maximal CBC of 15163.6 µg Cu2+/g protein. Besides, four peptide fractions of 10–30 kDa, 3–10 kDa, 1–3 kDa, and <1 kDa were recovered using ultrafiltration, among which the <1 kDa fraction had the highest CBC of 10852.00 ± 895.06 µgCu2+/g protein. A copper-binding peptide, Phe-Ile-Asp-Asp-Asp-Ala-Phe-Ile-Arg (1110 Da), was identified from this fraction using tandem mass spectrometry (MS/MS). As a whole, the proteolysate/peptides could be used for copper enhancement that could shield human body from copper inadequacy disorders.

中文翻译：

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来自鲑鱼副产品蛋白水解物的铜螯合肽

摘要 本研究的目的包括评估鲑鱼副产物蛋白水解物及其肽级分的铜结合能力 (CBC) 和氨基酸组成，优化水解条件，以及从蛋白水解物中鉴定铜结合肽。结果表明，在理想水解条件下（Neutrase，温度45°C，pH 7，酶：底物（E：S）比例为72.24 U/g蛋白，水解时间为8.02 h），蛋白水解物具有必不可少的氨基酸含量约为 38.7%，还显示了 15163.6 µg Cu2+/g 蛋白质的最大 CBC。此外，使用超滤回收了 10-30 kDa、3-10 kDa、1-3 kDa 和 <1 kDa 的四种肽级分，其中 <1 kDa 级分的 CBC 最高，为 10852.00 ± 895.06 µgCu2+/g 蛋白质。一种铜结合肽，Phe-Ile-Asp-Asp-Asp-Ala-Phe-Ile-Arg (1110 Da) 使用串联质谱 (MS/MS) 从该馏分中鉴定出来。总的来说，蛋白水解物/肽可用于铜增强，从而保护人体免受铜缺乏症的影响。