菜单 基因医生

该基因编码凝血因子xiia亚单位凝血因子xiii是凝血级联反应中最后被激活的酶原。血浆因子XIII是由2个a亚基和2个B亚基组成的异四聚体a亚基具有催化功能，b亚基不具有酶活性，可作为等离子体载体分子。血小板因子xiii仅由2个a亚单位组成，与血浆来源相同。在凝血酶和钙离子的存在下，血浆因子xiii分解其b亚单位，并产生与血小板因子xiii相同的活性酶因子xiia。这种酶作为转谷氨酰胺酶，催化纤维蛋白分子间的γ-谷氨酰-ε-赖氨酸交联形成，从而稳定纤维蛋白凝块它还将α-2-纤溶酶抑制剂或纤维粘连蛋白与纤维蛋白的α链交联因子xiii缺陷分为两类：i型缺陷，其特征是a和b亚单位均缺失；ii型缺陷，其特征是a亚单位单独缺失。这些缺陷会导致终身出血倾向、伤口愈合不良和习惯性流产。[由RefSeq提供，2008年7月]
This gene encodes the coagulation factor XIII A subunit. Coagulation factor XIII is the last zymogen to become activated in the blood coagulation cascade. Plasma factor XIII is a heterotetramer composed of 2 A subunits and 2 B subunits. The A subunits have catalytic function, and the B subunits do not have enzymatic activity and may serve as plasma carrier molecules. Platelet factor XIII is comprised only of 2 A subunits, which are identical to those of plasma origin. Upon cleavage of the activation peptide by thrombin and in the presence of calcium ion, the plasma factor XIII dissociates its B subunits and yields the same active enzyme, factor XIIIa, as platelet factor XIII. This enzyme acts as a transglutaminase to catalyze the formation of gamma-glutamyl-epsilon-lysine crosslinking between fibrin molecules, thus stabilizing the fibrin clot. It also crosslinks alpha-2-plasmin inhibitor, or fibronectin, to the alpha chains of fibrin. Factor XIII deficiency is classified into two categories: type I deficiency, characterized by the lack of both the A and B subunits; and type II deficiency, characterized by the lack of the A subunit alone. These defects can result in a lifelong bleeding tendency, defective wound healing, and habitual abortion. [provided by RefSeq, Jul 2008]