FIGURE 1.

The spectrum of the Hx-heme complex. The spectrum of the Hx-heme complex (4.35 μm) in the presence and absence of ZnSO₄ (100 μm) in sodium or ammonium bicarbonate buffer (20 mm, adjusted to pH 7.4 with dilute HCl) at 22 °C: a, spectrum recorded immediately after dilution into sodium bicarbonate buffer in the absence of Zn²⁺; b, in ammonium bicarbonate buffer 5 min after addition of Zn²⁺; c, in sodium bicarbonate buffer 143 min after addition of Zn²⁺; d, in ammonium bicarbonate buffer 153 min after addition of Zn²⁺; e, in sodium bicarbonate buffer 1,236 min after addition of Zn²⁺; and f, in ammonium bicarbonate buffer 1320 min after addition of Zn²⁺.