Efficiency of organic solvents on the ability of α2,3-sialyltransferase from Photobacterium sp. JT-ISH-224 to control a hydrolysis side reaction

Abstract

Enzymatic synthesis of oligosaccharides using specific sialyltransferases enables single-step glycosylation with high positional and anomeric structural selectivity. The α2,3-sialyltransferase cloned from the marine bacterium Photobacterium sp. JT-ISH-224 has unique and broad acceptor specificity, but this enzyme possesses not only sialyltransferase activity but also sialidase activity. To synthesize sialoside derivative effectively, only sialyltransferase activity is required. We report here that addition of organic solvents was effective to control the sialidase activity and a resulting product was not hydrolyzed. The enzyme was even active in the presence of acetonitrile, ethanol, methanol, or acetone. To determine the suitable concentrations of these organic solvents, only sialyltransferase activity could be allowed, and as a result, the stable synthesis of sialoside could be achieved.