1. Enhanced α-Zearalenol Hydrolyzing Activity of a Mycoestrogen-Detoxifying Lactonase by Structure-Based Engineering
- Author
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Huazhong Li, Weidong Liu, Jian Jin, Chen Yun, Tzu-Ping Ko, Guizhi Liu, Wei Peng, Rey-Ting Guo, Ya-Shan Cheng, Qian Li, Yingying Zheng, Wenting Liu, Zhongxia Xu, Jian-Wen Huang, and Chun-Chi Chen
- Subjects
0301 basic medicine ,chemistry.chemical_classification ,030102 biochemistry & molecular biology ,biology ,Chemistry ,Stereochemistry ,Rational design ,Substrate (chemistry) ,Mycoestrogen ,General Chemistry ,Catalysis ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Enzyme ,Biochemistry ,Catalytic triad ,Hydrolase ,Lactonase ,biology.protein ,Specific activity - Abstract
The enzyme ZHD101 from Clonostachys rosea hydrolyzes and deactivates the mycotoxin zearalenone (ZEN) and its zearalenol (ZOL) derivatives. ZHD101 prefers ZEN to ZOL as its substrate, but ZOL, especially the α-form, shows higher estrogenic toxicity than ZEN. To enhance α-ZOL selectivity, we solved the complex structures of ZHD101 with both ZOLs and modified several lactone-surrounding residues. Among the mutants, V153H maintained activity for ZEN but showed a 3.7-fold increase in specific activity against α-ZOL, with an ∼2.7-fold reduction in substrate affinity but a 5.2-fold higher turnover rate. We then determined two V153H/ZOL complex structures. Here, the α-ZOL lactone ring is hydrogen-bonded to the H153 side chain, yielding a larger space for H242 to reconstitute the catalytic triad. In conclusion, structure-based engineering was successfully employed to improve the ZHD101 activity toward the more toxic α-ZOL, with great potential in further industrial applications.
- Published
- 2016