Solubility variations of the recombinant urate oxidase.

A) Solubility of urate oxidase as a function of pH in 50 mM Tris buffer at 20°C without added salt. B) Solubility of urate oxidase as a function of temperature in 50 mM Tris buffer pH 8, taking into account variation of pH as a function of temperature with tris buffer (ΔpH/ΔT = −0.03°C⁻¹). C) Solubility of urate oxidase as a function of salt type and ionic strength in 50 mM Tris buffer pH 8 at 20°C. D) Solubility of urate oxidase as a function of polymer addition (PEG 8000 or Poloxamer P188) with and without salt at 20°C.