Figure 4.
pH-dependent asparaginyl-peptidase and aspartyl-peptidase activity of legumain. Bz-Asn-pNA (filled rectangles) and Ac-Tyr-Val-Ala-Asp-pNA (open triangles) turnover of super-activated legumain was measured in legumain reaction buffer at the indicated pH values at 310 K. Activity is represented by k cat/K m normalized to maximum activity (100%), which is obtained at pH 5.5 (n = 3, standard deviations indicated). The maximum activity was determined as k cat/K m = 7.3 ± 0.05 × 102 s−1 M −1, with k cat = 2 ± 0.5 s−1 and K m = 2.4 ± 0.1 mM.