A new l-arabinose isomerase with copper ion tolerance is suitable for creating protein-inorganic hybrid nanoflowers with enhanced enzyme activity and stability

Protein-inorganic hybrid nanoflowers were prepared using Cu²⁺, PBS buffer, and a copper ion tolerant l-arabinose isomerase that was derived from Paenibacillus polymyxa (PPAI). The expensive rare sugar l-ribulose or d-tagatose was prepared utilizing these nanoflowers with l-arabinose or d-galactose as the substrate, respectively. The PPAI hybrid nanoflowers showed better enzyme stabilities in both thermal and acidic conditions. Meanwhile, long term batch production was successful showing high stability using these hybrid nanoflowers, which achieved a conversion rate of 61.8% from l-arabinose to l-ribulose.