College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, China.
Toxins (Basel). 2020 Oct 29;12(11):680. doi: 10.3390/toxins12110680.
Ochratoxin A (OTA) is a toxic secondary metabolite produced mainly by spp. and spp. and commonly found in foodstuffs and feedstuffs. Carboxypeptidase A (CPA) can hydrolyze OTA into the non-toxic product ochratoxin α, with great potential to realize industrialized production and detoxify OTA in contaminated foods and feeds. This study constructed a expression vector of mature CPA (M-CPA) without propeptide and signal peptide. The results showed that the degradation rate of OTA by M-CPA was up to 93.36%. Its optimum pH was 8, the optimum temperature was 40 °C, the value of K was 0.126 mmol/L, and the maximum reaction rate was 0.0219 mol/min. Compared with commercial CPA (S-CPA), the recombinant M-CPA had an improve stability, for which its optimum temperature increased by 10 °C and stability at a wide range pH, especially at pH 3-4 and pH 11. M-CPA could effectively degrade OTA in red wine. M-CPA has the potential for industrial applications, such as can be used as a detoxification additive for foods and feeds.
赭曲霉毒素 A（OTA）是一种主要由 和 产生的有毒次级代谢物，普遍存在于食品和饲料中。羧肽酶 A（CPA）可以将 OTA 水解为无毒产物 ochratoxin α，具有很大的工业化生产潜力，可用于脱除污染食品和饲料中的 OTA。本研究构建了成熟 CPA（M-CPA）的无前肽和信号肽的 表达载体。结果表明，M-CPA 对 OTA 的降解率高达 93.36%。其最适 pH 为 8，最适温度为 40°C，K 值为 0.126mmol/L，最大反应速率为 0.0219mol/min。与商业 CPA（S-CPA）相比，重组 M-CPA 的稳定性有所提高，最适温度提高了 10°C，在宽 pH 范围内稳定性增强，尤其是在 pH 3-4 和 pH 11 时。M-CPA 可以有效降解红酒中的 OTA。M-CPA 具有工业化应用的潜力，可作为食品和饲料的解毒添加剂。
