赭曲霉毒素A降解酶Af-OTd的酶学性质分析  

Analysis of Enzymatic Properties of Ochratoxin A Degrading Enzyme Af-OTd

作　　者：宋佳 范寰[2] 闫雪 王文杰[2] 赵晨 Song Jia;Fan Huan;Yan Xue;Wang Wenjie;Zhao Chen(Academy of National Food and Strategic Reserves Administration,National Engineering Research Center for Grain Storage and Transportation,Beijing 100037;Tianjin Animal Science and Veterinary Research Institute,Tianjin 300381;New Hope Liuhe Co.,Ltd.,Key Laboratory of Feed and Livestock and Poultry Products Quality&Safety Control,Ministry of Agriculture,Chengdu 610023)

机构地区：[1]国家粮食和物资储备局科学研究院粮食储运国家工程研究中心,北京100037 [2]天津市畜牧兽医研究所,天津300381 [3]新希望六和股份有限公司农业农村部饲料及畜禽产品质量安全控制重点实验室,成都610023

出　　处：《中国食品学报》2022年第1期31-38,共8页Journal of Chinese Institute Of Food Science and Technology

基　　金：“十三五”国家重点研发计划项目(2016YFD0501207);天津市奶牛现代农业产业技术体系创新团队专项资金(ITTCRS2018022)。

摘　　要：赭曲霉毒素A(OTA)是一种广泛分布在食品中的真菌毒素,减少或脱除食品及其原料中的赭曲霉毒素A,对提高食品质量、保障国民食品安全具有重要意义。本实验室前期从粪产碱菌中获得可降解OTA的酰胺水解酶Af-OTd,本研究通过基因重组实现Af-OTd蛋白的高效表达,并对纯化的Af-OTd蛋白进行酶学性质分析。结果表明:纯化的Af-OTd酶对OTA的降解率达90%以上,降解活性受温度、pH值、酒精含量及金属离子的影响。该酶最适温度50℃,最适pH 7.5。酒精含量增加会导致酶活性下降,当酒精含量增至8%,剩余酶活几乎为0。1 mmol/L的金属离子Ca^(2+)、Co^(2+)、Cu^(2+)、Mg^(2+)、Mn^(2+)、Zn^(2+)、K^(+)及EDTA对该酶具有不同程度的抑制作用;微量的Co^(2+)、Zn^(2+)对Af-OTd酶活性有明显的促进作用。Ochratoxin A (OTA) is a fungal toxin widely distribute in food.Reducing or eliminating OTA in food and its raw materials is of great significance in improving food quality and ensuring national food safety.Previously,the amide hydrolase AF-OTd (Alcaligenes faecalis OTA degrading enzyme),which can degrade OTA,was identified from Alcaligenes faecalis in the laboratory.In this study,the protein AF-OTd was highly expressed through gene recombination,and the enzymatic properties of the purified AF-OTd protein were analyzed.The results showed that the degradation rate of the purified AF-OTd enzyme for OTA was over 90%,and the degradation activity was affected by temperature,p H,alcohol and metal ions.The optimal temperature and p H of the enzyme were 50℃and 7.5,respectively.Increase of alcohol content lead to a decrease of enzyme activity.When the alcohol content increased to 8%,the remaining enzyme activity was almost zero.1 mmol/L of metal ions Ca^(2+),Co^(2+),Cu^(2+),Mg^(2+),Mn^(2+),Zn^(2+),K^(+)and EDTA have different degrees of inhibition on the enzyme.At the same time,it was also found in this study that trace amounts of Co^(2+)and Zn^(2+)could significantly promote the activity of AF-OTd.

关 键 词：赭曲霉毒素A 表达纯化 降解酶 酶学性质 

分 类 号：TS201[轻工技术与工程—食品科学]