Figure 2.

Michaelis-Menten constants (K _m) of the proteasome in rat brain with age. Michaelis-Menten constants of the proteasome in rat brain plotted against age: K _m-values were obtained as described in Figure 1. (a) Chymotrypsin-like activity: R ² = 0.024, P = .291. (b) Trypsin-like activity: R ² = 0.189, P = .002. (c) Peptidylglutamyl peptidase activity: R ² = 0.060, P = .094. A P-value of less than  .05 was considered statistically significant.