Université Clermont Auvergne, CNRS, Sigma-Clermont, ICCF, Institut de Chimie de Clermont-Ferrand, F-63000 Clermont-Ferrand, France; Université Clermont Auvergne, CNRS, Laboratoire Microorganismes : Génome et Environnement, F-63000 Clermont-Ferrand, France.
Université Clermont Auvergne, CNRS, Sigma-Clermont, ICCF, Institut de Chimie de Clermont-Ferrand, F-63000 Clermont-Ferrand, France.
J Colloid Interface Sci. 2019 Jan 1;533:71-81. doi: 10.1016/j.jcis.2018.07.126. Epub 2018 Jul 29.
The development of new multifunctional materials integrating catalytically active and selective biomolecules, such as enzymes, as well as easily removable and robust inorganic supports that allow their use and reuse, is a subject of ongoing attention. In this work, the nitroreductase NfrA2/YncD (NR) from Bacillus megaterium Mes11 strain was successfully immobilized by adsorption and coprecipitation on layered double hydroxide (LDH) materials with different compositions (MgAl-LDH and ZnAl-LDH), particle sizes and morphologies, and using different enzyme/LDH mass ratios (Q). The materials were characterized and the immobilization and catalytic performance of the biohybrids were studied and optimized. The nitroreductase-immobilized on the nanosized MgAl-LDH displayed the best catalytic performance with 42-46% of catalytic retention and>80% of immobilization yield at saturation values of enzyme loading Cs ≈ 0.6 g NR/g LDH (Q = 0.8). The adsorption process displayed high enzyme-LDH affinity interactions yielding to a stable biohybrid material. The increase in the amount of enzyme loading favoured the catalytic performance of the biohybrid due to the better preservation of the native conformation. The biohybrid was reused several times with partial activity retention after 4 cycles. In addition, the biohybrid was successfully dried maintaining the catalytic activity for several weeks when it was stored in its dry form. Finally, thin films of NR@LDH biohybrid deposited on glassy carbon electrodes were evaluated as a modified electrode applied for nitro-compound detection. The results show that these biohybrids can be used in biotechnology applications to efficiently detect compounds such as dinitrotoluene. The search for new non-hazardous chemical designs preventing or reducing the use of aggressive chemical processes for human being and the environment is the common philosophy within sustainable chemistry.
将催化活性和选择性生物分子（如酶）与易于去除和坚固的无机载体集成到新型多功能材料中的开发，是一个持续关注的主题。在这项工作中，成功地将来自巨大芽孢杆菌 Mes11 菌株的硝基还原酶 NfrA2/YncD（NR）通过吸附和共沉淀固定在具有不同组成（MgAl-LDH 和 ZnAl-LDH）、粒径和形态的层状双氢氧化物（LDH）材料上，并使用不同的酶/LDH 质量比（Q）。对材料进行了表征，并研究和优化了生物杂种的固定化和催化性能。在纳米级 MgAl-LDH 上固定化的硝基还原酶表现出最佳的催化性能，在酶负载 Cs≈0.6 g NR/g LDH（Q=0.8）的饱和值时，保留了 42-46%的催化活性和>80%的固定化产率。吸附过程显示出酶-LDH 之间具有高亲和力相互作用，从而产生稳定的生物杂化物材料。增加酶的加载量有利于生物杂化物的催化性能，因为可以更好地保持天然构象。该生物杂化物经过 4 次循环后，仍可部分保留活性，多次重复使用。此外，生物杂化物在干燥状态下可以成功干燥并保持数周的催化活性。最后，将 NR@LDH 生物杂化物的薄膜沉积在玻碳电极上，作为一种修饰电极，用于检测硝基化合物。结果表明，这些生物杂化物可用于生物技术应用中，以有效地检测二硝基甲苯等化合物。在可持续化学中，寻找新的无危险化学设计以防止或减少对人类和环境具有侵略性的化学过程的使用，是一种共同的理念。
