Biochemical characterization of a thermostable uricase from Tengchong hot spring and its urate-lowering therapeutic potential

Uricase, a key enzyme in purine metabolism, is widely used for uric acid detection and for treating gout and hyperuricemia. To obtain a uricase with both high activity and thermal stability, we cloned and heterologously expressed a novel uricase gene (tc1-uox2) from the Tengchong hot spring metagenome and combined enzymatic characterization with molecular dynamics simulations. TC1-Uox2 exhibited optimal catalytic activity at 35 °C and pH 8.0. It showed remarkable thermal stability, retaining over 40% residual activity after 16 h at 40 °C and maintaining over 80% activity for 14 h at physiological temperature (37 °C). In vitro uric acid-lowering assays demonstrated that 1 µg/mL TC1-Uox2 reduced serum uric acid to below 360 µM within 20 min in whole-blood samples from six hyperuricemic patients. Comparative molecular dynamics simulations with rasburicase indicated that, based on RMSF, radius of gyration (Rg), and hydrogen-bond counts, TC1-Uox2 adopts a more compact overall structure. Free energy landscape (FEL) analysis further revealed that TC1-Uox2 occupies deeper and narrower energy basins, consistent with greater conformational rigidity and thermodynamic stability. These findings elucidate the structural basis of its enhanced thermostability. In summary, TC1-Uox2 is a high-activity, high-stability uricase candidate that represents a promising enzyme target for biotherapeutic intervention in hyperuricemia and illustrates the translational potential of extreme-environment metagenomics for metabolic disease applications.