Figure 4.

Immunoblot analysis of cleavage of normal FVa by APC/protein S in the presence of purified HDL or LDL. Purified human FVa (18 nM) was incubated with APC (4.3 nM), CaCl₂ (5 mM), 0.1% BSA, and protein S (58 nM) in the absence of lipoproteins (control lanes 2–5) or in the presence of HDL (260 μM PL) (lanes 6–9) or LDL (260 μM PL) (lanes 10–13). At the times indicated, aliquots were taken and analyzed by immunoblotting using anti–FVa heavy-chain antibodies.