FIGURE 8.

In vitro HO activity of purified SynHO1 versus PfHO. A, time-dependent (min) UV-visible absorbance changes of 10 μm heme bound to 20 μm SynHO1 or 100 μm PfHO. Samples contained 10 mm ascorbate, 1 μm catalase, 50 mm Tris·HCl (pH 8), and 100 mm NaCl. B, reverse-phase C₁₈ HPLC analysis of tetrapyrrole standards or reaction products of 10 μm heme incubated with 20 μm SynHO1 or 100 μm PfHO in 50 mm Tris·HCl (pH 8), 100 mm NaCl, 1 μm catalase, and either (i) 10 mm ascorbate or (ii) 10 μm Spin. or P. falciparum (Pf) Fd, 0.025 units/ml spinach FNR, and 100 μm NADPH.