Figure 6.

Kinetics of IDE-dependent degradation of insulin in the absence and presence of polyphenols at 37 °C. (a) Michaelis–Menten plots for insulin digests in the absence and presence of resveratrol were similar to one another, indicating that the polyphenol has no effect on IDE’s activity toward insulin. (b) Corresponding plots for the digestions in the absence and presence of EGCG clearly show that IDE’s activity decreased as the concentration of EGCG increased. Plots for polyphenol concentrations of 0, 20, and 40 μM are shown in green, red, and blue, respectively. Each data point represents the mean from three trials. The solid lines are fits to the Michaelis–Menten equation.