Sulfolobus solfataricus β-glycosidase-catalysed synthesis of sugar-alcohol conjugates in the presence of organic solvents

The thermostable beta-D-glycosidase from the archaeon Sulfolobus solfataricus was used for the glucosylation of secondary alcohols at high organic solvent concentrations. Alkyl glucoside products were analysed by one- and two-dimensional NMR. Using a range of racemic secondary alcohols and various hydrophilic organic solvents, small but significant substrate- and solvent-dependent changes in the RIS ratios of alkyl glucoside products were detected. The anomeric specificity of the enzyme was apparently affected by butan-2-one. A possible mechanistic model for solvent-induced changes at the active site is presented.