PH wave-front propagation in the urea-urease reaction
The urease-catalyzed hydrolysis of urea displays feedback that results in a switch from acid (pH ∼3) to base (pH ∼9) after a controllable period of time (from 10 to >5000 s). Here we show that the spatially distributed reaction can support pH wave fronts propagating with a speed of the order of 0.1-1 mm min-1. The experimental results were reproduced qualitatively in reaction-diffusion simulations including a Michaelis-Menten expression for the urease reaction with a bell-shaped rate-pH dependence. However, this model fails to predict that at lower enzyme concentrations, the unstirred reaction does not always support fronts when the well-stirred reaction still rapidly switches to high pH. © 2012 by the Biophysical Society.
Publication Source (Journal or Book title)
Wrobel, M., Bánsági, T., Scott, S., Taylor, A., Bounds, C., Carranzo, A., & Pojman, J. (2012). PH wave-front propagation in the urea-urease reaction. Biophysical Journal, 103 (3), 610-615. https://doi.org/10.1016/j.bpj.2012.06.020