Characterization of a maltooligosyl trehalose synthase from hyperthermophilic archaeon Sulfolobus tokodaii strain 7

Abstract:

[Objective] To clone the gene ST0929 encoding maltooligosyl trehalose synthase from the hyperthermophilic archaeon Sulfolobus tokodaii strain 7 and characterize the enzyme. [Methods] The ST0929 gene was amplified by PCR based on Sulfolobus tokodaii strain 7 ST0929 gene sequence and cloned into the expression vector pET-15b. The recombinant plasmid was transformed into E. coli BL21. After induced by IPTG (isopropyl-β-D-1-thiogalactoside), the bacterial pellet was sonicated and purified by affinity chromatography. The enzymatic properties were then measured. [Results] SDS-PAGE analysis showed that the molecular mass of the enzyme was about 83 kD. The optimal temperature was at 75 °C and pH at 5.0. Moreover, the enzyme exhibited notable pH and thermal stability and was resistant to additives and mental ions. Substrate specificity analysis showed that the enzyme could use maltodextrin and maltooligosaccharide as substrates but could not use maltose, chitooligosaccharide. [Conclusion] The recombinant enzyme described in this study suggest its potential in industrial production of trehalose.