Abstract: A modified uricase is described herein, as well as a method of reducing a level of uric acid by contacting a medium with the modified uricase. The modified uricase comprises a uricase polypeptide crosslinked by at least one bifunctional linking moiety that comprises a poly(alkylene glycol) moiety. A molecular weight of the bifunctional linking moiety is from about 1.5 kDa to about 4 kDa, and/or the modified uricase comprises a plurality of polypeptides having the amino acid sequence SEQ ID NO: 2. Further described is a polypeptide having the amino acid sequence SEQ ID NO: 2. A process of preparing the modified uricase is also described, comprising contacting the polypeptide with a crosslinking agent that comprises a poly(alkylene glycol) moiety and at least two aldehyde groups, to obtain a conjugate; and contacting the conjugate with a reducing agent.

Abstract: A modified DNase protein is described herein as well as pharmaceutical compositions comprising same, the modified DNase protein comprising a DNase polypeptide attached to at least two poly(alkylene glycol) moieties. Further described herein is a process of preparing a modified DNase protein, the process comprising: contacting the polypeptide with an agent that comprises a poly(alkylene glycol) attached to an aldehyde group, to obtain a conjugate of the polypeptide and the agent; and contacting the conjugate with a reducing agent.