Dextrin-aldehyde-based preparation of recyclable CDX-036 transaminase with high activity, stability and detailed...

Chiral amines are critical intermediates in pharmaceutical synthesis, with transaminases serving as efficient biocatalysts for their production. CDX-036, a well-characterized engineered transaminase, is widely used in the industrial synthesis of sitagliptin. However, high operational costs necessitate enzyme recyclability to enhance process economics. In this study, CDX-036 was immobilized onto dextrin aldehyde, a cost-effective and abundantly available support, to create a stable and reusable biocatalyst. Dextrin was oxidized using sodium periodate to yield dextrin aldehyde, confirmed by DNPH assay, FTIR, NMR, and SEM. The enzyme was immobilized via Schiff base formation with an optimal loading yield of 82% at a 1:5 enzyme-to-support ratio. Immobilized CDX-036 exhibited superior catalytic efficiency, achieving up to 92% conversion of pro-sitagliptin to sitagliptin in the first cycle-compared to up to 80% with the free enzyme. Notably, the immobilized enzyme retained high activity over five cycles, demonstrating excellent stability and reusability. Characterization by SEM, FTIR, and NMR confirmed successful immobilization. This method presents a scalable, economical, and industrially relevant strategy for enzyme reuse without compromising performance. To our knowledge, this is the first report detailing a robust immobilization strategy for CDX-036, directly applicable to sitagliptin synthesis at commercial scale.

The online version contains supplementary material available at 10.1007/s13205-025-04570-5.