Su Jing, Wang Tengfei, Ma Chunling, Li Zhongkui, Li Zhenzhen, Wang Ruiming
School of Food & Bioengineering, Qilu University of Technology, Jinan, 250300, China.
Biotechnol Lett. 2014 May;36(5):1009-13. doi: 10.1007/s10529-013-1450-9. Epub 2014 Feb 22.
Trehalose is a non-reducing disaccharide that has wide applications in the food industry and pharmaceutical manufacturing. Trehalose synthase (TreS) from Pseudomonas putida P06 catalyzes the reversible interconversion of maltose and trehalose and may have applications in the food industry. However, the catalytic mechanism of TreS is not well understood. Here, we investigated the structural characteristics of this enzyme by homology modeling. The highly conserved Asp294 residue was identified to be critical for catalytic activity. In addition, flexible docking studies of the enzyme-substrate system were performed to predict the interactions between TreS and its substrate, maltose. Amino acids that interact extensively with the substrate and stabilize the substrate in an orientation suitable for enzyme catalysis were identified. The importance of these residues for catalytic activity was confirmed by the biochemical characterization of the relevant mutants generated by site-directed mutagenesis.
海藻糖是一种非还原性二糖，在食品工业和制药生产中有着广泛应用。恶臭假单胞菌P06来源的海藻糖合酶（TreS）催化麦芽糖和海藻糖的可逆相互转化，可能在食品工业中有应用。然而，TreS的催化机制尚未完全清楚。在此，我们通过同源建模研究了该酶的结构特征。高度保守的Asp294残基被确定对催化活性至关重要。此外，进行了酶-底物系统的柔性对接研究，以预测TreS与其底物麦芽糖之间的相互作用。确定了与底物广泛相互作用并以适合酶催化的方向稳定底物的氨基酸。通过定点诱变产生的相关突变体的生化特性证实了这些残基对催化活性的重要性。
