Figure 4. Effect of a metal-catalyzed oxidative system (Fe³⁺/ascorbate) on ICDH activity and concentration.

A, Time course of ICDH activity in Prochlorococcus sp. PCC 9511 cell extracts with the following additions: ▪, control cells (no addition); •, 0.2 mM FeCl3; ▴, 0.2 mM FeCl3 +1 mM ascorbate; ⧫, 0.2 mM FeCl3 +5 mM ascorbate; ▾, 0.2 mM FeCl3 +10 mM ascorbate. Values are the average of three biological samples, each of them measured in triplicate. Error bars correspond to the standard deviation. B, Western blotting of ICDH in Prochlorococcus sp. PCC 9511 cell extracts after 60 min of incubation under the following additions: Control, no addition; 1, 0.2 mM FeCl3; 2, 0.2 mM FeCl3 +1 mM ascorbate; 3, 0.2 mM FeCl3 +5 mM ascorbate; 4, 0.2 mM FeCl3 +10 mM ascorbate. The quantification of bands is shown below the picture, assigning an arbitrary value of 100 to the control conditions. C, Coomasie-stained gel corresponding to a duplicate of that used for the Western blotting shown in B.