Figure 4: Nature Communications

Fig. 4

From: Engineered factor Xa variants retain procoagulant activity independent of direct factor Xa inhibitors

Fig. 4

Snake–human factor X(a) variants. a An alignment of region His91-Asp102 in human FX (WT-FX) and FX variants A (FX-A), B (FX-B), and C (FX-C) is shown. The sequences inserted between His91 and Tyr99 originate from P. textilis venom FX (FX-A), from T. carinatus venom FX (FX-B), or from P. textilis isoform FX (FX-C). b Proteins (3 µg per lane) were subjected to SDS-PAGE under reducing conditions and visualized by staining with Coomassie Brilliant Blue. Lane 1: plasma-derived FXa; lane 2: recombinant wild-type FXa; lane 3: FXa variant A; lane 4: FXa variant B; lane 5: FXa variant C. The protein bands corresponding to the heavy chain derived from α or β FXa (α/β), the FXa light chain (LC), and the apparent molecular weights (kDa) of the standards are indicated. While autoproteolytic excision of the C-terminal portion of FXa-α (residues 436–447) yields the β form of FXa, both isoforms are functionally similar with respect to prothrombinase assembly, prothrombin activation, antithrombin recognition, and peptidyl substrate conversion62. The purified products of wt-FXa and FXa variants B and C migrate predominantly as FXa-β; FXa variant A migrates as a 50/50 mixture of α and β FXa. The data are representative of two independent experiments