Production of a new sucrose derivative by transglycosylation of recombinant Sulfolobus shibatae β-glycosidase

The gene encoding β-glycosidase of the hyperthermophilic archaea Sulfolobus shibatae (SSG) was expressed in Escherichia coli. Recombinant SSG (referred to as rSSG hereafter) was efficiently purified, and its transglycosylation activity was tested with lactose as a donor and various sugars as acceptors. When sucrose was used as an acceptor, we found a distinct intermolecular transglycosylation product and confirmed its presence by TLC and high performance anion exchange chromatography (HPAEC). The sucrose transglycosylation product was isolated by paper chromatography, and its chemical structure was determined by ¹H and ¹³C NMR. The sucrose transfer product was determined to be β-d-galactopyranosyl- (1→6)-α-d-glucopyranosyl-β-d-fructofuranoside with a galactose molecule linked to sucrose via a β-(1→6)-glycosidic bond.