Characterization of a d-tagatose 3-epimerase from Caballeronia fortuita and its application in rare sugar production.

Characterization of a d-tagatose 3-epimerase from Caballeronia fortuita and its application in rare sugar production.
Int J Biol Macromol. 2019 Jul 19;:
Authors: Li S, Chen Z, Zhang W, Guang C, Mu W
Abstract
Recently, rare sugars have caused extensively attention due to their beneficial physiological functions and potential applications in food systems and medical fields. Ketose 3-epimerase (KEase) can catalyze reversibly the epimerization between ketoses which is the pivotal enzyme in Izumoring strategy and an effective tool for biological production of rare sugars. In this work, a KEase from Caballeronia fortuita was recombined and characterized as a d-tagatose 3-epimerase (DTEase, EC 5.1.3.31). The recombinant DTEase displayed the highest activity at pH 7.5 and 65 °C in the presence of Co2+. The recombinant DTEase displayed the relatively high thermostability and the half-life (t1/2) was determined to be 7.13, 5.13, and 1.05 h at 50, 55, and 60 °C, respectively. The recombinant DTEase had a wide substrate specificity and the specific activities towards d-tagatose, d-allulose, d-fructose and l-sorbose were measured to be 801 ± 2.3, 450 ± 2.7, 270 ± 1.5 and 55 ± 1.8 U mg-1, respectively. So far, the recombinant DTEase exhibited the highest specific activity towards d-tagatose compared with other reported KEases. Furthermore, the recombinant DTEase could produce 314.2 g/L d-sorbose from 500 g/L d...

Source: International Journal of Biological Macromolecules - July 18, 2019 Category: Biochemistry Authors: Li S, Chen Z, Zhang W, Guang C, Mu W Tags: Int J Biol Macromol Source Type: research