Specific anion effects on urease activity: A Hofmeister study.

The effects of a range of electrolytes on the hydrolysis of urea by the enzyme urease is explored. The autocatalytic behavior of urease in unbuffered solutions and its pH clock reactions are studied. The concentration dependence of the experimental variables is analyzed in terms of specific ion-enzyme interactions and hydration. The results offer insights into the molecular mechanisms of the enzyme, and on the nature of its interactions with the electrolytes. We found that urease can tolerate mild electrolytes in its environment, while it is strongly inhibited by both strong kosmotropic and strong chaotropic anions. This study may cast light on an alternative therapy for Helicobacter pylori infections and contribute to the design of innovative materials and provide new approaches for the modulation of the enzymatic activity.