Institute of Biosciences and BioResources, National Research Council, Via Pietro Castellino 111, 80131, Naples, Italy.
Novamont SpA, loc. La Fagianeria Snc, Piana di Monte Verna, Caserta, Italy.
Sci Rep. 2023 Sep 15;13(1):15338. doi: 10.1038/s41598-023-42597-x.
Peroxidases are widespread key antioxidant enzymes that catalyse the oxidation of electron donor substrates in parallel with the decomposition of HO. In this work, a novel tomato peroxidase, named SAAP2, was isolated from MicroTom cell cultures, purified, and characterised. The enzyme was identified with 64% sequence coverage as the leprx21 gene product (suberization-associated anionic peroxidase 2-like) from Solanum lycopersicum, 334 amino acids long. Compared to other plant peroxidases, SAAP2 was more active at elevated temperatures, with the optimal temperature and pH at 90 °C and 5.0, respectively. Furthermore, the enzyme retained more than 80% of its maximal activity over the range of 70-80 °C and the presence of NaCl (1.0-4.5 M). It also exhibited broad pH versatility (65% relative activity over the pH range 2.0-7.0), acid-tolerance (80% residual activity after 22 h at pH 2.0-7.0), high thermostability (50% residual activity after 2 h at 80 °C) and proteolytic resistance. SAAP2 exhibited exceptional resistance under thermo-acidic conditions compared to the horseradish peroxidase benchmark, suggesting that it may find potential applications as a supplement or anti-pollution agent in the food industry.
过氧化物酶是广泛存在的关键抗氧化酶，能够在分解 HO 的同时催化电子供体底物的氧化。在这项工作中，从 MicroTom 细胞培养物中分离出一种新型的番茄过氧化物酶，命名为 SAAP2，并对其进行了纯化和表征。该酶的序列覆盖率为 64%，被鉴定为来自番茄的 leprx21 基因产物（与木质素化相关的阴离子过氧化物酶 2 样），由 334 个氨基酸组成。与其他植物过氧化物酶相比，SAAP2 在高温下更具活性，最适温度和 pH 值分别为 90°C 和 5.0。此外，该酶在 70-80°C 的范围内保留了超过 80%的最大活性，并且在 1.0-4.5 M 的 NaCl 存在下也具有活性。它还表现出广泛的 pH 适应性（在 pH 2.0-7.0 范围内相对活性为 65%）、耐酸性（在 pH 2.0-7.0 下 22 小时后残留活性为 80%）、高热稳定性（在 80°C 下 2 小时后残留活性为 50%）和抗蛋白酶性。与辣根过氧化物酶基准相比，SAAP2 在热酸性条件下表现出异常的抗性，这表明它可能在食品工业中作为补充剂或抗污染剂具有潜在的应用价值。
