Formulation and storage of bacillus fastidious uricase as diagnosis enzymes

Abstract:

Objective：To explore the formulation and storage methods for bacillus fastidious uricase as a diagnosis enzyme. Methods： Lyophilized powders of this uricase containing protective additives，and solutions of this uricase containing preservatives，were stored at -18℃ or 4℃. Enzyme activity was monitored at proper intervals. Homotetramers and homodimers of this uricase were resolved by polyacrylamide gel electrophoresis（PAGE），and were stained separately for both proteins and enzyme activities. Results：The lyophilized powders and solution preparations of this uricase yielded the corresponding residual enzyme activities of 12% and 100%，respectively，after storage at 4℃ for 28 days，and the residual enzyme activities of 24% and 92%，respectively，after storage at -18℃ for 28 days.The use of trehalose，sucrose and mannitol as the protective additives in lyophilized powders gave the residual enzyme activities of 100%，76% and 43%，respectively，after storage for 56 days at -18℃. The use of NaN3 and benzoic acid as the preservative in the solutions gave the residual enzyme activities of 99% and 82%，respectively，after storage for 56 days at 4℃. By PAGE analyses of lyophilized powders of low activity，less active homotetramers but more inactive homodimers were observed. Conclusion：This uricase as a diagnosis reagent can be prepared in solutions containing NaN3 for storage at 4℃.