Figure 4

Functional characterization of the recombinant M. suis sPPase. (A) Activation of M. suis rPPase by Mg²⁺. The rPPase (10 ng/μl) was incubated for 5 min in the same buffer containing different concentrations of MgCl₂. Values represent mean values ± standard deviation of five independent experiments. (B) Differences in the activation of rPPase by Mg²⁺, Mn²⁺, or Zn²⁺. Recombinant PPase (10 ng/μl) was incubated for 5 min in the same buffer containing 5 mM MgCl₂, 5 mM MnCl₂ and 5 mM MgCl₂, respectively. Activation of M. suis rPPase by MgCl₂ was set as 100%. Values represent mean values ± standard deviation of triplicates. (C) Inhibition of M. suis rPPase activity by Ca²⁺ and EDTA. Recombinant PPase (10 ng/μl) was incubated for 5 min in buffer containing 5 mM MgCl₂ alone and with 5 mM CaCl₂ and 5 mM EDTA, respectively. Activity value of M. suis rPPase with MgCl₂ alone was set as 100%. Values represent mean values ± standard deviation of triplicates. (D) pH value dependency of the M. suis rPPase activity. PPase activity was measured using 50 mM MgCl₂ and buffers with increasing pH values. Data represent mean values ± standard deviation from five independent experiments. (E) Activity of M. suis rPPase using different PPi concentrations. Activity was measured with fixed concentrations of rPPase (10 ng/μl) and 50 mM MgCl₂ at a pH of 9.0. Values represent mean values ± standard deviation of five independent experiments.