Cloning, expression and characterization of the maltooligosyl trehalose synthase from the archaeon Sulfolobus tokodaii.

The maltooligosyl trehalose synthase gene from the hyperthermophilic archaeon Sulfolobus tokodaii strain 7 was cloned and the recombinant peotein was expressed in E. coli. The protein was purified to homogeneity by nickel column chromatography. The archaeal enzyme could catalyze an intramolecular transglycosylation reaction and convert the glycosidic bond at the reducing end of dextrins from α-1, 4 (reducing end) into α-1, 1 (non-reducing end). The most suitable temperature was 75°C and the optimal pH was 5. Substrate specificity investigation revealed that maltodextrin and maltooligosaccharide were used as substrates by the enzyme but maltose, chitooligosaccharide, sucrose and β-cyclodextrin weren't used.