Figure 7. Incorporation of [2-¹⁴C]glycine and [4-¹⁴C]ALA into haem and the assay of FC enzymic activity in the organellar and cytosolic fractions.

The cytosolic (shaded bars) or solubilized organellar (empty bars) fractions were incubated with [2-¹⁴C]glycine or [4-¹⁴C]ALA to measure incorporation into haem. FC enzymic activity was assayed in these fractions using ⁵⁹FeCl₃ and protoporphyrin as substrates. Results are expressed in terms of radioactivity in haem for the total cytosolic or solubilized organellar fraction obtained from 6 ml of parasite culture. (A) FC enzymic activity; 1, heat-denatured parasite fractions (control); 2, total enzymic activity. (B) [2-¹⁴C]Glycine incorporation into haem; 1, [1-¹⁴C]glycine incorporation (control); 2, [2-¹⁴C]glycine incorporation. (C) [4-¹⁴C]ALA incorporation into haem; 1, heat-denatured parasite fractions (control); 2, native parasite fractions; white bar, cytosol; shaded bar, solubilized organellar fraction.