Department of Biochemistry, Faculty of Life Sciences, Z.H. College of Engg. & Tech., Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
Department of Biochemistry, Faculty of Life Sciences, Z.H. College of Engg. & Tech., Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
Mater Sci Eng C Mater Biol Appl. 2020 Jul;112:110883. doi: 10.1016/j.msec.2020.110883. Epub 2020 Mar 21.
Candida rugosa lipase (CRL) was treated with surfactants and immobilized onto the novel formulated magnetic graphene anchored silica nanocomposite (FeO/SiO/Gr NC). For this purpose, the surface of lipase was initially coated with Triton-X 100 and cetyltrimethylammonium bromide surfactants, to stabilize enzyme in its open form and was then adsorbed onto aminated FeO/SiO/Gr NC. Glutaraldehyde (GA) was then utilized to cross-link the adsorbed lipase onto the NC. The fabricated NC and conjugated lipase was characterized by various techniques such as FT-IR, XRD, TGA, SEM, TEM, CLSM, CD and Fluorescence spectroscopy. The magnetic character of the as-synthesized NC was verified by AGM investigation. CD and fluorescence spectroscopic analysis demonstrated slight structural rearrangements in lipase upon conjugation. The surfactant stabilized immobilized lipase demonstrated significantly enhanced thermostability, tolerance to various metal ions and inhibitors. The immobilization yield obtained owing to lipase interfacial activation by Triton X 100 and CTAB was remarkably enhanced by 6-folds and 3-folds, respectively which were remarkably higher in comparison to free immobilized lipase. The fabricated nanobiocatalysts were employed to synthesise green apple flavour ester, ethyl valerate via esterification reaction. Triton X 100 stabilized immobilized lipase was a better performer in yielding green apple flavour ester, demonstrating about 90% ester yield as compared to 78% yield obtained by CTAB stabilized immobilized lipase preparation. The obtained outcomes suggested that enzyme structure was stabilized by the GA treatment if executed in the absence or in the presence of detergent, and that, in the company of detergent, a conformation of the lipase with the exposed active center to the medium provided an aggrandized catalytic performance.
皱褶假丝酵母脂肪酶（CRL）经过表面活性剂处理并固定在新型配方的磁性石墨烯锚定二氧化硅纳米复合材料（FeO/SiO/Gr NC）上。为此，首先用 Triton-X 100 和十六烷基三甲基溴化铵表面活性剂处理脂肪酶的表面，以使其在开放形式下稳定，并随后吸附到氨基化的 FeO/SiO/Gr NC 上。然后利用戊二醛（GA）将吸附的脂肪酶交联到 NC 上。通过各种技术，如 FT-IR、XRD、TGA、SEM、TEM、CLSM、CD 和荧光光谱法对制备的 NC 和共轭脂肪酶进行了表征。通过 AGM 研究验证了合成的 NC 的磁性。CD 和荧光光谱分析表明，在共轭过程中脂肪酶的结构略有重排。表面活性剂稳定的固定化脂肪酶表现出显著增强的热稳定性、对各种金属离子和抑制剂的耐受性。由于 Triton X 100 和 CTAB 对界面的激活作用，固定化脂肪酶的固定化产率显著提高了 6 倍和 3 倍，与游离固定化脂肪酶相比显著提高。制备的纳米生物催化剂被用于通过酯化反应合成青苹果风味酯，即戊酸乙酯。Triton X 100 稳定的固定化脂肪酶在生成青苹果风味酯方面表现更好，表现出约 90%的酯收率，而 CTAB 稳定的固定化脂肪酶的收率为 78%。所得结果表明，在没有或存在洗涤剂的情况下，通过 GA 处理稳定了酶结构，如果在洗涤剂的存在下，提供了暴露于介质的活性中心的脂肪酶构象提供了增强的催化性能。
