Inorganic supports have attracted increased attention in enzyme immobilization since they not only improve enzyme stability but also reduce the final cost of enzymatic reactions. Herein, we explored the suitability of the amino-functionalized zeolite/SiO₂ materials to co-immobilize trypsin–chymotrypsin mixture. For this purpose, the trypsin–chymotrypsin mixture was co-immobilized on the amino-functionalized zeolite/SiO₂ materials and the immobilization yield was 80.7 ± 7.6%. The pre-support and its modification were characterized by several techniques. Besides, the charges of the materials were investigated by zeta potentials at pH 5.0. As expected, the zeta potentials shifted from − 24.4 to − 8.16 mV after amino functionalization. Following immobilization, whereas the optimum pH (9.0) was not changed, the optimum temperature shifted from 50 to 40 °C. On the other hand, the immobilized trypsin–chymotrypsin showed comparatively higher thermal stability and storage stability than the soluble trypsin–chymotrypsin. The kinetic parameters were also calculated, however, while no significant change was observed in V_max, K_m value increased, which means that the affinity of enzyme to the substrate decreased after immobilization. Most strikingly, the residual activity of immobilized trypsin–chymotrypsin was 58% after eight repeated cycles. In conclusion, the preliminary experiments inferred that the amino-functionalized zeolite/SiO₂ particles can be suitable and helpful support for trypsin–chymotrypsin immobilization.

Graphic Abstract

中文翻译：

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用于胰蛋白酶-胰凝乳蛋白酶共固定的氨基官能化沸石/SiO2 材料的制备和表征

无机载体在酶固定化方面引起了越来越多的关注，因为它们不仅提高了酶的稳定性，而且降低了酶促反应的最终成本。在此，我们探索了氨基官能化沸石/SiO ₂材料共固定胰蛋白酶-胰凝乳蛋白酶混合物的适用性。为此，将胰蛋白酶-胰凝乳蛋白酶混合物共固定在氨基官能化沸石/SiO _{2 上}材料的固定化率为 80.7±7.6%。预支撑及其修改的特征在于几种技术。此外，材料的电荷通过 pH 5.0 下的 zeta 电位进行研究。正如预期的那样，在氨基功能化后，zeta 电位从 - 24.4 mV 变为 - 8.16 mV。固定后，虽然最佳 pH 值 (9.0) 没有改变，但最佳温度从 50 °C 变为 40 °C。另一方面，固定化胰蛋白酶-胰凝乳蛋白酶显示出比可溶性胰蛋白酶-胰凝乳蛋白酶更高的热稳定性和储存稳定性。然而，还计算了动力学参数，但未观察到 V _max、K _{m 的}显着变化值增加，这意味着固定化后酶对底物的亲和力降低。最引人注目的是，固定化胰蛋白酶-胰凝乳蛋白酶的残留活性在八次重复循环后为 58%。总之，初步实验推断，氨基官能化沸石/SiO ₂颗粒可以为胰蛋白酶-胰凝乳蛋白酶固定提供合适且有用的支持。

图形摘要