Western blot of FVa inactivation by wild-type APC and 306-314AAAA-APC.

(A) Wild-type APC, 200 pmol/L. (B) 306-314AAAA-APC, 2 nmol/L. FVa at a concentration of 20 nmol/L was incubated in 50 mmol/L HEPES, pH 7.4, 100 mmol/L NaCl, 5 mmol/L CaCl₂, 0.1 mmol/L MnCl₂, 0.1% BSA with 25 μmol/L phospholipid vesicles. APC was added and aliquots were removed at 1 through 40 minutes. The Western blot was developed as described in “Materials and methods.” Molecular weight standards are indicated on the left in kilodalton units. On the right fragments of the FVa heavy chain are labeled. HC = intact FVa heavy chain.