In this study, peptides were prepared from defatted Antheraea pernyi (Lepidoptera: Saturniidae) pupa protein via hydrolysis with combined neutral proteases. Single-factor tests and response surface methodology (RSM) were used to determine the optimal hydrolysis condition suitable for industrial application. Optimal hydrolysis of the defatted pupa protein was found to occur at an enzyme concentration of 4.85 g/liter, a substrate concentration of 41 g/liter, a hydrolysis temperature of 55°C, and a hydrolysis time of 10 h and 40 min. Under these conditions, the predicted and actual rates of hydrolysis were 45.82% and 45.75%, respectively. Peptides with a molecular weight of less than 2,000 Da accounted for 90.5% of the total peptides generated. Some of the peptides were antioxidant peptides as revealed by sequencing and functional analysis. The antioxidant activity of the mixed peptides was subsequently confirmed by an antioxidant activity assay. The results showed that peptides with high antioxidant activity could be obtained from the hydrolysis of A. pernyi pupa protein.

中文翻译：

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组合中性蛋白酶酶解脱脂柞蚕（鳞翅目：天蚕科）蛹蛋白产生具有抗氧化活性的肽

在本研究中，通过结合中性蛋白酶的水解，从脱脂柞蚕（鳞翅目：土星科）蛹蛋白中制备肽。使用单因素测试和响应面法（RSM）来确定适合工业应用的最佳水解条件。脱脂蛹蛋白的最佳水解条件为：酶浓度为4.85 g/L，底物浓度为41 g/L，水解温度为55℃，水解时间为10 h 40 min。在此条件下，预测水解率为45.82%，实际水解率为45.75%。分子量小于2000Da的肽占生成的肽总量的90.5%。通过测序和功能分析表明，一些肽是抗氧化肽。随后通过抗氧化活性测定证实了混合肽的抗氧化活性。结果表明，柞蚕蛹蛋白水解可得到具有高抗氧化活性的肽。