Uricase sequences and methods of treatment

A uricase monomer comprising:

• (a) an amino acid sequence having at least 95% sequence identity to the amino acid sequence set forth in SEQ ID NO:1 and comprising two engineered cysteine residues;
• (b) two polyethylene glycol (PEG) molecules, wherein each PEG is conjugated to each unique engineered cysteine residue;
• (c) a deletion of a threonine residue at position 2, wherein the position numbering is relative to the amino acid sequence of SEQ ID NO:27;
• and
• (d) a truncation of the C-terminus, wherein the truncation removes an endogenous C-terminal cysteine residue, and wherein the uricase retains enzymatic activity.