Fig. 3.
Effect of substrate concentrations on ACE2 activity. (a) The assay was performed with different ACE2 substrate concentrations (11.25, 5.63, 2.81, and 1.41 μM) for 16 h incubation using mouse rACE2 concentrations between 0 and 200 ng/ml. Graph depicts the concentrations of mouse rACE2 versus the activity (RFU) at different substrate concentrations. (b) Standard curves generated for mouse rACE2 with 11.25 or 5.63 μM ACE2 substrate concentrations. A highly linear relationship between mouse rACE2 and the RFU exists for both substrate concentrations (R 2 = 0.9994, p < 0.001 for 11.25 μM; R 2 = 0.9903, p < 0.001 for 5.63 μM)