Recombinant Expression and Characterization of an Alkali-tolerant UDP-Glycosyltransferase from Solanum lycopersicum and Its Biosynthesis of Gastrodin.

Gastrodin is the main bioactive component of , which has many excellent pharmacological activities. In this study, UDP-glycosyltransferase from (SlyUGT) was overexpressed, purified and characterized, and it can be used for biosynthesis of gastrodin. The SlyUGT maximum enzyme activity was 29.48 mU/ml, and its relative molecular weight was about 78.5 kDa. The SlyUGT was purified 16.1-fold by GST affinity resin with an overall recovery of 53.9% and specific activity of 20.9 mU/mg. The optimal temperature of SlyUGT was 40C, and it exhibited excellent thermal stability at 35C and 40C. Furthermore, the SlyUGT had the highest activity at pH 9.5 and good pH stability at pH 5.5-10.5. The enzyme can tolerate low concentrations of DMSO and UDP. In addition, the values of KM and Vmax were found to be 0.65 mM and 74.60 mU/mg respectively. The SlyUGT could convert pHBA into gastrodin by using UDP-glucose as a sugar donor. Under the optimal biosynthesis conditions, the gastrodin production reached 559.83 mg/l, and the corresponding molar conversion rate reached 97.82%. The results showeald that SlyUGT has potential application value in the preparation of gastrodin.