FIG 6.

Effect of cellular components from Synechocystis on Adc1- or Adc2-mediated arginine decarboxylase activity and spermidine production. (A) Detection of Adc1 and Adc2 expressed in Synechocystis mutants by Western blotting. Arrowheads point to the bands corresponding to histidine-tagged Adc1 (filled arrowhead) and Adc2 (open arrowhead). (B) Total protein isolated from Synechocystis stained with Coomassie brilliant blue R-250. Each lane in panels A and B corresponds to one biological replicate. (C and D) Enzymatic activity measurements. Arginine was added to extracts of ko1ko2, ko1ko2/1ox, and ko1ko2/2ox. Amounts of agmatine (C) and spermidine (D) were determined after 1 h. Each value corresponds to the mean ± SD (n = 3). Significant differences between ko1ko2 and ko1ko2/1ox or ko1ko2/2ox were analyzed by Student's t test (**, P < 0.01). ND stands for not detected.