Improved Alkyl Glycoside Synthesis by trans-Glycosylation through Tailored Microenvironments of Immobilized β-Glucosidase

We present how the microenvironment can directly improve biocatalytic selectivity of immobilized β-glucosidase. β-Glucosidase from Thermotoga neapolitana was immobilized on a variety of functionalized off-stoichiometric thiol-ene (OSTE) particles, where highest activities were observed for thiol and imidazole functional particles. Compared to the soluble enzyme, the selectivity (rs/rh) between trans-glycosylation of p-nitrophenyl β-D-glucopyranoside (pNPG) with 1-propanol over hydrolysis was increased by a factor of 2–3 using particles containing imidazole (rs/rh of 6.7) and carboxylic acid moieties (rs/rh of 9.2), respectively. These results demonstrate clearly that enzyme selectivity depends directly on the local environment of the enzyme with the support