FXIII-A2* is cleaved and inactivated by plasmin. FXIII (100 nM), with or without prior activation by thrombin (400 nM), was mixed with varying concentrations of plasmin (100 pM to 100 nM) for 3 hours, and analyzed by western blot against FXIII A and B subunits. (A) Blot against the A subunit of pFXIII-A2*, with thrombin activation. (B) Blot against the A subunit of pFXIII-A2B2. (C) Blot against the B subunit of pFXIII-A2*, with thrombin activation. (D) Blot against the B subunit of pFXIII-A2B2. (E) Time course of cleavage of FXIII-A2* by plasmin (90 nM). (F) Transglutaminase activity (left axis) of FXIII-A2* after incubation with plasmin (90 nM) and the relative amount of intact FXIII-A2* (right axis), determined by quantifying the intensity of the band at 83 kDa. FXIII-A* was calculated as a percentage of total signal in the lane using densitometry. The error bars represent standard error of the mean (SEM). n = 3 for all experiments. Thr, thrombin.
