Fig. 2.
Sta is competitive with ATP. To determine the inhibitory mechanism of Sta, concentration-response curves of kinase activity were measured over a range of ATP concentrations. (A) Increasing concentrations of Sta increase the apparent Km for ATP without an effect on Vmax, suggesting a competitive model by Michaelis-Menten kinetics. (B) Using the Lineweaver-Burk model, the lines all intersect at the same y-intercept with varying x-intercepts, mathematically suggesting a competitive model. (C) Testing the data under tight-binding equations shows a mixed model of inhibition that is predominantly competitive with ATP.