Improving esterification activity of Burkholderia cepacia lipase encapsulated in silica by bioimprinting with substrate analogues
Bioimprinting is a promising, though relatively unexplored, approach to improving the performance of enzymes. In this study, bioimprinting with substrate analogues of fatty acids was systematically conducted to improve the esterification activity of Burkholderia cepacia lipase that had undergone a sol–gel immobilization procedure with methyltrimethoxysilane (MTMS) and tetramethoxysilane (TMOS) as the precursors. The specific activity of the bioimprinted lipases was 3682.0 μmol h−1 mg protein, which was a 47.9- and 2.5-fold increase over the free and non-imprinted immobilized lipases, respectively. Compared to the free and non-imprinted immobilized lipases, bioimprinted lipases exhibited better thermal stability, and their activity did not change after being incubated at 60 °C for 12 h. Bioimprinted lipases were more easily affected by alcohol than the non-imprinted ones, whose specific activity could be markedly enhanced by ethanol, isopropanol and n-butanol by factors of 1.23-, 1.28- and 1.12-fold, respectively. The reasons for the improvement of imprinted enzyme activity are also discussed based on the surface structure, specific surface area and average pore diameter of the silane particles.
Journal: Process Biochemistry - Volume 44, Issue 2, February 2009, Pages 177–182