Fig. 2: Evaluation of partitioning, kinetic characterization, and pH change generated by urease activity inside the droplets.
From: Sustained enzymatic activity and flow in crowded protein droplets
a Confocal microscope image of Alexa Fluor 488-labeled urease at 1.0 μM inside the PEG-BSA droplets (scale bar is 20 μm). b, c Urease activity measurement in the droplets and supernatant and in the supernatant only and Michelis–Menten curves of urease in the droplets and supernatant and in the buffer. Inset of panel c, kinetic parameters values of droplets containing-urease compared to those of free urease in the buffer. The concentration of urease in the activity measurements is 1 μM in the droplets and supernatant and 0.3 nM in a buffer. Data are represented as mean values ± SD from three independent experiments (n = 3). d Visualization of the pH change in the droplets containing 1 μM urease at different times using two different concentrations of substrate (50 and 100 mM urea) along with the control (no substrate). Scale bars are 50 μm. e Evaluation of the pH change over time for droplets with a radius above 65 μm containing 1 μM urease at different urea concentrations. Data are represented as mean values ± SD from three independent droplets (n = 3). f pH change inside the droplets at 450 s at different urea concentrations and 1 μM urease. Data are represented as mean values ± SD from five isolated droplets (n = 5).
