Coagulation factor XIII B chain (F13B)

Coagulation factor XIII B chain is a plasma protein encoded by the F13B gene that forms part of the factor XIII heterotetramer (A2B2), essential for the final steps of the blood clotting cascade.[1][2][3][4][5] The B chain acts as a regulatory and carrier subunit: it stabilizes the catalytic A subunits in circulation until activation by thrombin and calcium ions, at which point the B subunits dissociate, enabling the A subunits to cross-link fibrin and stabilize blood clots.[1][2][3][5] Deficiency of the B chain results in a rare bleeding disorder with impaired wound healing, and F13B is also implicated in other physiological functions such as angiogenesis, bone formation, and immune response.[1][2][3][5] While therapeutic targeting is not typical except for replacement in deficiency, it is a crucial molecule for hemostasis.[1][3][5]

Other names

FXIIIBFibrin-stabilizing factor B subunitProtein-glutamine gamma-glutamyltransferase B chainTransglutaminase B chainTGaseCoagulation factor XIII, B polypeptide

Replacement therapy to restore clot stability and coagulation in deficiency