Abstract Browning is an obstacle in industrial development of sweet potato. Peroxidase from sweet potato cv. ‘Zhongshu 1′ was purified and analyzed by chromatography and mass spectrometry. Peroxidase from ‘Zhongshu 1′ sweet potato was a monomeric protein with 37.2 kDa. A binding site of peroxidase to guaiacol was discovered using molecular docking, with Arg61 and Ala191 being near the active region important for guaiacol catalysis. The IC50 values of ascorbic acid, sodium metabisulfite and glutathione were (1.97 ± 0.03)×10−4, (2.99 ± 0.07)×10−4 and (6.87 ± 0.12)×10-3 mol L-1, respectively. These compounds were competitive (ascorbic acid, (1.96 ± 0.03) ×10−4 mol L-1), non-competitive (sodium metabisulfite, (1.08 ± 0.03) ×10−4 mol L-1) and uncompetitive inhibitors (glutathione, (10.78 ± 0.05)×10-3 mol L-1) of peroxidase. Fluorescence spectrum showed the static quenching type of three inhibitors. The change of residues near the active site in peroxidase contributed to prevention of browning.

中文翻译：

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'中熟1号'甘薯过氧化物酶结构分析及抑制机制

摘要 褐变是甘薯产业发展的障碍。来自甘薯 cv. 的过氧化物酶。'中枢1'经色谱和质谱法纯化和分析。'中熟1号'甘薯过氧化物酶是一种单体蛋白，分子量为37.2 kDa。使用分子对接发现了过氧化物酶与愈创木酚的结合位点，Arg61 和 Ala191 靠近对愈创木酚催化很重要的活性区域。抗坏血酸、焦亚硫酸钠和谷胱甘肽的IC50值分别为(1.97±0.03)×10-4、(2.99±0.07)×10-4和(6.87±0.12)×10-3 mol L-1。这些化合物具有竞争性（抗坏血酸，(1.96 ± 0.03) ×10−4 mol L-1）、非竞争性（焦亚硫酸钠，(1.08 ± 0.03) ×10−4 mol L-1）和非竞争性抑制剂（谷胱甘肽， (10.78 ± 0.05)×10-3 mol L-1) 过氧化物酶。荧光光谱显示了三种抑制剂的静态猝灭型。过氧化物酶活性位点附近残基的变化有助于防止褐变。