Department of Bioengineering, School of Environmental & Biological Engineering, Nanjing University of Science and Technology, Nanjing, China.
Prep Biochem Biotechnol. 2024 Jan;54(1):103-114. doi: 10.1080/10826068.2023.2209884. Epub 2023 May 15.
Gamma-aminobutyric acid (GABA) is an vital neurotransmitter, and the reaction to obtain GABA through biocatalysis requires coenzymes, which are therefore limited in the production of GABA. In this study, polyacrylamide hydrogels doped with chitosan and waste toner were synthesized for glutamate decarboxylase (GAD) and coenzyme co-immobilization to realize the production of GABA and the recovery of coenzymes. Enzymatic properties of immobilized GAD were discussed. The immobilized enzymes have significantly improved pH and temperature tolerance compared to free enzymes. In terms of reusability, after 10 repeated reuses of the immobilized GAD, the residual enzyme activity of immobilized GAD still retains 100% of the initial enzyme activity, and the immobilized coenzyme can also be kept at about 32%, with better stability and reusability. And under the control of no exogenous pH, immobilized GAD showed good performance in producing GABA. Therefore, in many ways, the new composite hydrogel provides another way for the utilization of waste toner and promises the possibility of industrial production of GABA.
γ-氨基丁酸（GABA）是一种重要的神经递质，通过生物催化获得 GABA 的反应需要辅酶，因此 GABA 的产量受到限制。在这项研究中，合成了掺杂壳聚糖和废墨粉的聚丙烯酰胺水凝胶，用于谷氨酸脱羧酶（GAD）和辅酶的共固定化，以实现 GABA 的生产和辅酶的回收。讨论了固定化 GAD 的酶学性质。与游离酶相比，固定化酶的 pH 和温度耐受性有了显著提高。在可重复使用性方面，在 10 次重复使用固定化 GAD 后，固定化 GAD 的剩余酶活性仍保留初始酶活性的 100%，固定化辅酶也可保持在 32%左右，具有更好的稳定性和可重复使用性。并且在没有外源 pH 控制的情况下，固定化 GAD 在 GABA 的生产中表现出良好的性能。因此，在许多方面，新型复合水凝胶为废墨粉的利用提供了另一种途径，并有望实现 GABA 的工业化生产。
