High-yield and simple production of a ferritin-tagged urate oxidase with enhanced catalytic stability and yield

Urate oxidase (Uox) has great potential in biotechnology. However, the exploration of Uox with superior stability and its simple preparation with high yield remains challenging. By fusing human ferritin with the Uox from the extremophile Deinococcus radiodurans, a novel 24-polymeric Uox (DrUox-F) with excellent properties was achieved. The DrUox-F with 98 % purity was obtained through low-speed centrifugation with the yield of 890 mg/L, representing the highest yield currently reported. Remarkably, DrUox-F preserved 100 % activity after 35 days at pH 10, which was significantly superior to DrUox. Furthermore, no significant activity loss was observed following 318 days of storage at 4 °C. The lyophilized DrUox-F power retained over 90 % of original activity after 280 days of storage at room temperature. Notably, the half-life was extended approximately 40-fold (from 41 h to 1880 h) through the addition of mannitol as an exogenous stabilizer. Molecular docking results revealed that mannitol could specifically bind to multiple regions on DrUox-F, with hydrogen bonds as the dominant interactions. Thus, DrUox-F, with superior cost-effectiveness, high efficiency, and enhanced stability, provides a breakthrough solution for addressing the critical limitations of Uox.