Effects of Modification of Amino Groups with Poly(Ethylene Glycol) on a Recombinant Uricase from Bacillus fastidiosus

After modification with monomethoxyl-poly(ethylene glycol)-5000, a recombinant intracellular uricase from Bacillus fastidiosus ATCC 29604 showed residual activity of about 65%, a thermo-inactivation half-life >85 h, a circulating half-life about 20 h in rats in vivo, consistent effects of common cations, and consistent optima for reaction temperature and pH. Thus, this uricase can be formulated via modification with monomethoxyl-poly(ethylene glycol).