(254f) Activity Improvement of D-Psicose-3-Epimerase from Agrobacterium tumefaciens CGMCC 1.1488 By Site-Directed Mutagenesis

Authors: 
Chen, X., Paper and Bioprocess Engineering
Liu, S., SUNY College of Environmental Science and Forestry
Yuan, Z., Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences
Xu, J., Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences
The enzyme D-psicose-3-epimerase catalyzes the conversion of C3-epimerization from fructose to allulose (D-psicose). Due to the relatively low allulose conversion rate, the improvement of enzymatic activity by site-directed evolution was carried out in this experiment. The DPEase-C58 from Agrobacterium tumefaciens CGMCC 1.1488 was supplied to the protein structure comparison and sequence alignment with DTE from Pseudomonas cichorii, whose crystal structure and the complex with D-fructose had been determined, to conduct the sites mutagenesis. The two sites of saturation mutation of H228 and T231 were carried out. At first round 5 mutants with 20% relevant higher than wide-type were obtained by high-throughout screening method.