Introduction of disulfide bonds to stabilize AgUricase based on its crystal structure. a The introduction of disulfide bonds based on the structural model of WT AgUricase (PDB code 2YZB). Chain A, green; chain B, cyan; chain C, magenta; chain D, orange. b Cartoon model showing the disulfide bond design. Monomer–monomer, dimer–dimer, and intra-subunit disulfide bonds were generated by introducing cysteine pair mutations based on the crystal structure of WT AgUricase