Table S1.

Buffer-dependent activity of IDE at low pH

BufferpHActivity, nmol/min/mg IDE
Na acetate5.06No activity
Na citrate5.05No activity
MES5.1111.8
Na acetate5.48No activity
Na citrate5.508.9
MES5.6271.1
MES6.0868.9
Tris7.456.9
  • All buffers were at 50 mM. Assays were conducted with 10 ┬ÁM Abz-GGFLRKHGQ-Eddnp. pH values were determined from dummy reaction mixtures containing 20% DMF in place of substrate. In a separate experiment, the Abz substrate was completely cleaved, and the total fluorescence change measured at the different pH values. There was no effect of pH on the total fluorescence change.