An imprinted cross-linked enzyme aggregate (iCLEA) of sucrose phosphorylase: combining improved stability with altered specificity.

The industrial use of sucrose phosphorylase (SP), an interesting biocatalyst for the selective transfer of α-glucosyl residues to various acceptor molecules, has been hampered by a lack of long-term stability and low activity towards alternative substrates. We have recently shown that the stability of the SP from Bifidobacterium adolescentis can be significantly improved by the formation of a cross-linked enzyme aggregate (CLEA). In this work, it is shown that the transglucosylation activity of such a CLEA can also be improved by molecular imprinting with a suitable substrate. To obtain proof of concept, SP was imprinted with α-glucosyl glycerol and subsequently cross-linked with glutaraldehyde. As a consequence, the enzyme's specific activity towards glycerol as acceptor substrate was increased two-fold while simultaneously providing an exceptional stability at 60 °C. This procedure can be performed in an aqueous environment and gives rise to a new enzyme formulation called iCLEA.