FIGURE 2.

Dissociation of heme from the Hx-heme complex in ammonium bicarbonate buffer (20 mm, pH 7. 8, 15 °C) in the presence and absence of Ni²⁺. A, Hx-heme complex (4.14 μm) with 100 μm NiCl₂. The arrows indicate the change in absorption maxima with time at 0, 1240, 2900, 4300, 5200, 6800, and 11,000 min. B, Hx-heme complex (4.42 μm) with no metal ions added. The arrows indicate the change in absorption maxima with time at 0 min, 1660, 3000, 5600, 9900, and 15,700 min.