A mild one-pot self-assembly approach to encapsulating enzymes into metal-organic framework with Asp-boosted enzymatic performance for clean production

The strategies based on enzyme immobilization into/on metal-organic frameworks (MOFs) have been widely developed, but they still face some challenges in practical applications, such as limited recycle times, low loading efficiency. In this work, aspartate aminotransferase (AspAT), branched-chain aminotransferase (BCAT), polyvinyl pyrrolidone/aspartate (PA), cobalt ions and sodium 2-amino terephthalate were one-pot mixed in water at room temperature, and self-assembled to encapsulate the enzymes into cobalt-amino terephthalate framework (CAF) in 15 min. Compared with free enzymes, the biocomposite (A&B&PA@CAF) exhibited superior performances such as high encapsulation efficiency (55%), reusability (≥12), and resistance capacity to harsh conditions. Meanwhile, the activity recovery (AR) value (59.4%) of the biocomposite without adding polyvinyl pyrrolidone and aspartate was almost half of that (108.2%) of A&B&PA@CAF, and this enhancement was further demonstrated to be from Asp action via 1H-NMR and UV–Vis. To investigate the general applicability of this approach, the other aminases were also de novo immobilized with all their AR values reached more than 117%, even 180% for ω-transaminase. This study provided a sustainable and green approach for clean production of the significant chiral amine compounds.