SDS-PAGE analysis of rTFPI incubated with thrombin. rTFPI was incubated with thrombin in TBS at 37°C with the final concentrations of 2.6 mg/mL and 0.05 mg/mL, respectively. SDS-PAGE of the digest was performed as described in Materials and Methods. (A), Nonreducing condition; (B), reducing condition. See text for nomenclature of band 1, band 2, and band 3.