脂肪酸分子印迹对sol-gel固定化脂肪酶酯化活性和胶体结构的影响  

Effect of Fatty Acid Bioimprinting on the Esterification Activity of Sol-gel Encapsulated Lipase and the Structure of Gel Matrices

作　　者：杨江科[1] 曹雄文[1] 舒钟瑶[1] 

机构地区：[1]分子生物物理教育部重点实验室、华中科技大学生命科学与技术学院,武汉430074

出　　处：《分子催化》2010年第1期77-81,共5页Journal of Molecular Catalysis(China)

基　　金：国家“863”项目(2007AA05Z417,2009AA03Z232)

摘　　要：基于sol-gel工艺的生物印迹对提高脂肪酶在非水相体系中的活性,扩大其应用范围具有重要作用.本研究以乙烯基三甲氧基硅烷(VTMOS)和四甲氧基硅烷(TMOS)为前趋体,系统考察了脂肪酸印迹分子对sol-gel脂肪酶固定化率和活性的影响,获得了最优的工艺条件.当VTMOS/TMOS为7∶1时,印迹后脂肪酶的比酶活和总酶活分别达到3311.0μmol/h/mg和2506.9μmol/h/gGel,比未印迹同摩尔比的固定化脂肪酶分别提高了2.06和1.79倍.系统考察了脂肪酸生物印迹效应和胶体结构对固定化酶表观活性的影响.氮气吸附—解吸附分析和扫描电镜观察表明,随着脂肪酸分子的参入,固定化脂肪酶颗粒平均孔径增大,对底物的传质阻力逐渐降低,但比表面积和孔体积的变化并不显著;印迹酶平均颗粒直径明显减小,各有机硅烷单体之间的成键能力减弱.表明脂肪酶活性的增加主要来源于疏水性脂肪酸侧链引起的脂肪酶的界面激活效应(生物印迹效应),同时固定化颗粒孔径的改变增加了底物和酶分子的结合,提高了固定化酶的表观活性.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 vinyltrime-thoxysilane （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 mol/h/mg proteins and 2506.9 mol/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.

关 键 词：脂肪酶 脂肪酸 分子印迹 界面激活 孔径 

分 类 号：O643.3[理学—物理化学]