Improvement of aldehyde tolerance and sequential aldol condensation activity of deoxyriboaldolase via immobilization on interparticle pore type mesoporous silica

Deoxyriboaldolase from Klebsiella pneumonia (KpDERA) was immobilized on interparticle pore type mesoporous silica (IMS), which consists of aggregates of hexagonally close-packed silica nanoparticles. Incubation of the free KpDERA in 300 mM acetaldehyde resulted in a decrease in the free enzyme activity to 20% of the initial activity after incubation for 30 min. No activity was observed after 90 min incubation. In contrast, the IMS-immobilized KpDERA retained more than 50% of its activity after 30 min and 11% activity after 90 min incubation. The product yield of a sequential aldol condensation reaction, which is central to the production of pharmaceutically important intermediates, was found to be higher for IMS-immobilized KpDERA than for the free enzyme. These results suggest the potential utility of IMS as an immobilization support for DERA.