Hu Junqiang, Wang Gang, Hou Mingxuan, Du Shilong, Han Jun, Yu Yangguang, Gao Hongxia, He Dan, Shi Jianrong, Lee Yin-Won, Mohamed Sherif Ramzy, Dawood Dawood H, Hong Qing, Liu Xin, Xu Jianhong
Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs /Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing210014, People's Republic of China.
College of Life Science, Nanjing Agriculture University, Nanjing210095, People's Republic of China.
J Agric Food Chem. 2023 Feb 8;71(5):2411-2420. doi: 10.1021/acs.jafc.2c06410. Epub 2023 Jan 26.
Zearalenone (ZEN) is an estrogenic mycotoxin most frequently found in cereals that can cause reproductive disorders in livestock and pose a severe threat to animal husbandry. In this study, we isolated a ZEN-degrading strain from soil and found that ZenH, a hydrolase, is responsible for the hydrolysis of ZEN through comparative proteomics and biochemical studies. ZenH exhibited the highest similarity with lactone hydrolase ZHD607 from at 21.52%. ZenH displayed maximal enzymatic activity at pH 7.0 and 55 °C with a Michaelis constant of 12.64 μM. The catalytic triad of ZenH was identified as S117-D142-H292 by molecular docking and site-directed mutagenesis. ZenH catalyzed the hydrolysis of ZEN to a novel metabolite, (,)-4-hydroxy-2-(10-hydroxy-6-oxoundec-1-en-1-yl)-7-oxabicyclo[4.2.0]octa-1,3,5-trien-8-one, which exhibited significantly lower estrogenic toxicity than ZEN. This study illustrates a novel ZEN-degrading enzyme and reveals a new degradation product. Furthermore, the enzyme showed good potential for detoxifying ZEN during food processing.
玉米赤霉烯酮（ZEN）是一种雌激素类霉菌毒素，最常见于谷物中，可导致家畜生殖紊乱，对畜牧业构成严重威胁。在本研究中，我们从土壤中分离出一株降解ZEN的菌株，并通过比较蛋白质组学和生化研究发现，水解酶ZenH负责ZEN的水解。ZenH与来自的内酯水解酶ZHD607的相似度最高，为21.52%。ZenH在pH 7.0和55°C时表现出最大酶活性，米氏常数为12.64μM。通过分子对接和定点诱变确定ZenH的催化三联体为S117-D142-H292。ZenH催化ZEN水解为一种新的代谢产物，（，）-4-羟基-2-（10-羟基-6-氧代十一碳-1-烯-1-基）-7-氧杂双环[4.2.0]辛-1,3,5-三烯-8-酮，其雌激素毒性明显低于ZEN。本研究阐明了一种新型的ZEN降解酶，并揭示了一种新的降解产物。此外，该酶在食品加工过程中对ZEN解毒具有良好的潜力。
