Fig 5. Time course of the recovery of DPP-4 activity following dissociation of trelagliptin from the preformed DPP-4-inhibitor complex.
A preformed enzyme-inhibitor complex (where [DPP-4] = 50 nmol/L and trelagliptin concentration is as shown in the plot) was diluted 50-fold into a solution containing 2 mmol/L GP-pNA substrate (approximately 17x Km). Absorbance readings were taken every 10 seconds. Inset: Replot of the apparent dissociation rate constant, k’, against trelagliptin concentration used to estimate koff from the Y-intercept according to Eq 7.