Topic summary
Factor XIII
Factor XIII, or fibrin stabilizing factor, is a plasma protein and zymogen. It is activated by thrombin to factor XIIIa which crosslinksfibrin in coagulation. Deficiency of XIII worsens clot stability and increases bleeding tendency.
Human XIII is a heterotetramer. It consists of 2 enzymatic A peptides and 2 non-enzymatic B peptides. XIIIa is a dimer of activated A peptides.