FIG. 2.

Stability of cell-associated iron after acquisition from pyoverdin or pyochelin. (A and B) Control (A) and Ga(NO₃)₃-pretreated (B) HL-60 cells were incubated with [⁵⁹Fe]pyoverdin for 1 h and then were repetitively washed and resuspended in buffer alone (○) or buffer containing 300 μM apo-pyoverdin (▵) or 100 μM apo-pyochelin (□). Cell-associated ⁵⁹Fe was then determined over time. (C and D) control (C) and Ga(NO₃)₃-pretreated (D) HL-60 cells were incubated with [⁵⁹Fe]pyochelin for 1 h and then repetitively washed and resuspended in buffer alone (○) or buffer containing 300 μM apo-pyoverdin (▵) or 100 μM apo-pyochelin (□). The cell-associated ⁵⁹Fe concentration was then determined over time. Curves shown are representative of three separate experiments for each condition.