Hydrophobic adsorption and covalent immobilization of Candida antarctica lipase B on mixed-function-grafted silica gel supports for continuous-flow biotransformations
Hydrophobic adsorption and covalent immobilization of Candida antarctica lipase B on mixed-function-grafted silica gel supports for continuous-flow biotransformations
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DOI：
10.1016/j.procbio.2013.05.002
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发表时间：
2013-07-01
影响因子：
4.4
通讯作者：
Poppe, Laszlo
中科院分区：
文献类型：
--
作者：
Boros, Zoltan;Weiser, Diana;Poppe, Laszlo
固体载体吸附是提高脂肪酶力学性能和催化性能的一种简单有效的方法。脂肪酶与载体表面的共价结合提高了固定化生物催化剂的活性寿命。我们的研究表明，接枝具有多种功能的介孔硅胶是南极念珠菌（Candida antarctica, CaLB）脂肪酶B吸附和共价结合的理想载体。在苯基功能化的硅胶上吸附CaLB可显著提高其比活性，而在氨基烷基修饰的硅胶上吸附CaLB可与合适的试剂进行共价结合，其比活性仅为中等。此外，在苯基硅烷和氨基烷基硅烷混合物改性的硅胶上吸附可显著提高CaLB的产率。此外，CaLB吸附在苯基/氨基烷基修饰的表面上，然后用戊二醛（GDA）作为交联剂处理，提供了一种增强耐久性的生物催化剂。吸附和交联的CaLB耐洗涤剂洗涤，否则会使吸附的CaLB制剂物理失活。在外消旋1-苯乙醇rac-1a和1-苯乙胺rac-1b的连续流动动力学分辨率下，我们最好的固定化CaLB变体的催化性能，包括温度依赖行为，与两种商用CaLB生物催化剂在0到70℃之间进行了比较。(C) 2013 Elsevier Ltd.版权所有。
Adsorption onto solid supports has proven to be an easy and effective way to improve the mechanical and catalytic properties of lipases. Covalent binding of lipases onto the support surface enhances the active lifetime of the immobilized biocatalysts. Our study indicates that mesoporous silica gels grafted with various functions are ideal supports for both adsorptive and covalent binding for lipase B from Candida antarctica (CaLB). Adsorption of CaLB on phenyl-functionalized silica gels improved in particular its specific activity, whereas adsorption on aminoalkyl-modified silica gels enabling covalent binding with the proper reagents resulted in only moderate specific activity. In addition, adsorption on silica gels modified by mixtures of phenyl- and aminoalkyl silanes significantly increased the productivity of CaLB. Furthermore, CaLB adsorbed onto a phenyl/aminoalkyl-modified surface and then treated with glutardialdehyde (GDA) as cross-linking agent provided a biocatalyst of enhanced durability. Adsorbed and cross-linked CaLB was resistant to detergent washing that would otherwise physically deactivate adsorbed CaLB preparations. The catalytic properties of our best immobilized CaLB variants, including temperature-dependent behavior were compared between 0 and 70 degrees C with those of two commercial CaLB biocatalysts in the continuous-flow kinetic resolutions of racemic 1-phenylethanol rac-1a and 1-phenylethanamine rac-1b. (C) 2013 Elsevier Ltd. All rights reserved.