Enzyme Microb Technol. 2026 Apr 23;199:110883. doi: 10.1016/j.enzmictec.2026.110883. Online ahead of print.
ABSTRACT
The synthesis of chiral alcohols is crucial for pharmaceutical applications. This study employed ion gelation and biomimetic mineralization to co-immobilize glucose dehydrogenase (GDH) and carbonyl reductase (CR), producing a chitosan-calcium pyrophosphate hybrid nanoflower enzyme (CR/GDH-@Ca₂P₂O₇) for synthesizing the chiral alcohol compound ethyl (S)-4-chloro-3-hydroxybutyrate. This study optimized the synthesis conditions for nanoflower enzymes, including metal ion type and concentration, TPP and chitosan concentration, and enzyme concentration. The CR/GDH-@Ca₂P₂O₇ enzyme was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), confirming successful immobilization of the dual enzyme and the formation of a high-surface-area flower-like nanostructure. Compared to the free enzyme, CR/GDH-@Ca₂P₂O₇ exhibited enhanced pH and temperature stability. Particularly under acidic conditions, its catalytic performance significantly improved, indicating that the chitosan carrier enhances the enzyme’s tolerance in acidic environments. Simultaneously, CR/GDH-@Ca₂P₂O₇ displayed enhanced substrate affinity and a higher Vmax value, with its catalytic efficiency (Kcat/Km) increasing to 3.25 times that of the free enzyme. After six cycles of reuse, the catalytic activity of CR/GDH-@Ca₂P₂O₇ still retained 60%. These results suggested that chitosan-integrated nanoflower enzymes serve as highly efficient multifunctional catalysts for industrial biocatalysis, particularly suited for acidic applications.
PMID:42033909 | DOI:10.1016/j.enzmictec.2026.110883