Figure 5

Effects of pH on AprA and AprA-PPC activity and stability with or without Ca2+. (A) The optimal pH for AprA activity (filled square) and AprA-PPC activity (empty square) without Ca2+; (B) pH stability of AprA with (filled triangle) or without (empty triangle) Ca2+; (C) pH stability of AprA-PPC with (filled circle) or without (empty circle) Ca2+. The measurements were performed in three independent experiments. Error bars represent standard deviations.