Contributions of FXIIIa to clot stability

Contributions of FXIIIa to clot biochemical and mechanical stability. FXIIIa cross-linking of plasma proteins (i.e., α2-antiplasmin [α2-AP]) increases the resistance of the clot to fibrinolysis. Cross-linking of the fibrin α- (purple) and γ-chains (green) stiffens fibrin fibers and increases the mechanical stability of the clot. Increased mechanical stability renders the clot more resistant to shear forces. α-chain cross-linking enables RBC retention during clot contraction.