Fig 3

Effect of hemin and other putative substrates on ATPase activity of ABCB10.

(A) Relative ATPase activity of ABCB10 at increasing concentrations of hemin. Data normalized to the apo condition. Data from at least three independent experiments, p = 0.05. (B) Representative enzyme-coupled assay of MsbA showing inhibition by 100 μM hemin (blue curve), but no effect by ZnMP (5 μM, red curve). Data normalized to the highest intensity (Absorbance value at time 0). (C) Relative ATPase activity of ABCB10 in the presence of either 5 μM ZnMP or 5 μM Hemin, and in the simultaneous presence of both porphyrins (5 μM each). Data normalized to the apo condition. Data from three independent experiments, with a significant difference between all the conditions (p = 0.05). (D) ABCB10 ATPase activity was measured in the absence (apo) or presence of either 1 mM reduced (GSH) or oxidized (GSSG) glutathione, or 0.5 mM delta-aminolevulinic acid (ALA). ZnMP was used as a positive control at a concentration of 5 μM. Data from at least three independent experiments, p = 0.05.