YANG Jiangke, CAO Xiongwen, SHU Zhongyao

(Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science and Technology, Wuhan 430074, China)

Abstract: Bioimprinting enzymes in sol-gel matrices is a promising though so far relatively unexplored approach to improve the performance of enzymes. In this study, bioimprinting with substrate analogues of fatty acid was systematically conducted to improve the esterification activity of lipase in sol-gel immobilization procedure with vinyltrimethoxysilane (VTMOS) and tetramethoxysila (TMOS) as the precursors. Under the optimized condition (VTMOS/TMOS=7:1), the specific activity and total activity of the bioimprinted lipases was 3311.0 µmol/h/mg proteins and 2506.9 µmol/h/g gel, which was 2.06 - and 1.79 - fold of the non-imprinted immobilized lipases, respectively. Fourier transformed infrared spectroscopy, nitrogen adsorption-desorption assays, and gel matrix surface characterization showed that the bioimprinting molecule triggered lipase to change from the closed to the open conformation, and contributed to creating sol-gel matrices that were more porous and with less mass transfer resistance structure, apparently improving the activity of encapsulated lipase.

Keywords: Lipase; Fatty acid; Bioimprinting; Interfacial activation; Pore diameter;

Email: jiangke_yang@yahoo.com.cn

Journal of Molecular Catalysis, Vol. 24, Issue 1, 2010, 77~81