Department of Microbiology, Faculty of Biological Technology, Shahid Beheshti University, Tehran 19839-63113, Iran.
Young Researchers and Elite Club, Maragheh Branch Islamic Azad University, Maragheh 55197-47591, Iran.
Biomolecules. 2019 Sep 18;9(9):502. doi: 10.3390/biom9090502.
Immobilization of enzymes is a promising approach for the cost-effective application of enzymes. Among others, noncovalent but unleachable approaches for immobilization are one of the most favorable and crucial approaches. Herein, silica nanoparticles are modified by (3-aminopropyl)triethoxysilane (APTES) to generate amino-functionalized silica nanoparticles. Then, the amine functionalities are converted to bifunctional amino acid via post-modification that has zwitterionic properties. This nanostructure with the new functional theme is employed to immobilize lipase at room temperature with no further post-modification or cross-linking. This immobilization method is further compared with the metal chelate-based immobilization approach on the same support. The biocatalytic activity of the immobilized lipase is examined under various conditions. The encapsulation of lipase through amino acid-functionalized silica nanoparticles exhibited enhanced stability for the immobilized lipase at higher temperatures and unneutral pHs.
酶的固定化是一种具有成本效益的酶应用的有前途的方法。其中，非共价但不可洗脱的固定化方法是最有利和关键的方法之一。在此，通过（3-氨丙基）三乙氧基硅烷（APTES）修饰二氧化硅纳米粒子以生成氨基功能化的二氧化硅纳米粒子。然后，通过后修饰将胺官能团转化为具有两性离子性质的双官能氨基酸。这种具有新功能主题的纳米结构用于在室温下固定化脂肪酶，无需进一步的后修饰或交联。将这种固定化方法与相同载体上基于金属螯合的固定化方法进行比较。在各种条件下检查固定化脂肪酶的生物催化活性。通过氨基酸功能化的二氧化硅纳米粒子包封脂肪酶，固定化脂肪酶在较高温度和非中性 pH 值下表现出增强的稳定性。
