Fig. 8. Effect of PMA on the membrane compartmentalisation of WT-ACE and GPI-ACE. CHO cells transfected with either WT-ACE or GPI-ACE were incubated for 7 hours in the presence of batimastat (10 µM) with or without PMA (1 µM). Lipid rafts were prepared by buoyant sucrose density-gradient centrifugation in the presence of batimastat (10 µM) as described in Materials and Methods. The sucrose gradients were fractionated in 0.5 ml aliquots (0, insoluble pellet; 1, bottom of tube; 9, top of tube) and each fraction was assayed for ACE activity with BzGly-His-Leu as substrate. (A) Distribution of WT-ACE activity in sucrose gradient fractions. (B) Distribution of GPI-ACE activity in sucrose gradient fractions. Results are the mean ± s.d. of three experiments.