Hada M, Kaminski M, Bockenstedt P, McDonagh J
Blood. 1986 Jul;68(1):95-101.
Factor XIIIa crosslinks a limited number of substrates via epsilon(gamma-glutamyl)-lysyl bond formation. It crosslinks fibrin to itself, alpha 2-plasmin inhibitor and fibronectin to fibrin, and fibronectin to collagen. Results presented here show that plasma von Willebrand factor (vWF) is a substrate for factor XIIIa and can be crosslinked to fibrin during gel formation. vWF-fibrin crosslinking was studied in purified systems and in plasma with 125I-vWF and 131I-fibrinogen. vWF incorporation into fibrin increased with time or increasing factor XIIIa. After electrophoresis of dissolved clots, distribution of 125I and 131I was measured and showed that vWF was crosslinked to the alpha chain of fibrin and entered the high-mol-wt alpha polymer. vWF-fibrin crosslinking decreased the initial rate of alpha polymer formation. Crosslinking of vWF polymer to itself could not be demonstrated under physiologic conditions but occurred if vWF was reduced first. Factor XIIIa catalyzed incorporation of putrescine into both monomeric and polymeric vWF. Altogether, these studies indicate that factor XIIIa can readily form covalent bonds between glutamine in vWF and lysine in fibrin alpha chains. This reaction occurs readily in vitro when plasma clotting is slow and may occur in vivo under similar conditions.
凝血因子ⅩⅢa通过形成ε（γ-谷氨酰）-赖氨酰键交联有限数量的底物。它使纤维蛋白自身交联，使α2-纤溶酶抑制剂和纤连蛋白与纤维蛋白交联，以及使纤连蛋白与胶原蛋白交联。此处呈现的结果表明，血浆血管性血友病因子（vWF）是凝血因子ⅩⅢa的一种底物，并且在凝胶形成过程中可与纤维蛋白交联。利用125I-vWF和131I-纤维蛋白原在纯化系统和血浆中研究了vWF-纤维蛋白交联。vWF掺入纤维蛋白的量随时间或凝血因子ⅩⅢa增加而增加。溶解的凝块经电泳后，测量125I和131I的分布，结果显示vWF与纤维蛋白的α链交联并进入高分子量α聚合物中。vWF-纤维蛋白交联降低了α聚合物形成的初始速率。在生理条件下无法证明vWF聚合物自身交联，但如果vWF先被还原则会发生自身交联。凝血因子ⅩⅢa催化腐胺掺入单体和聚合的vWF中。总之，这些研究表明凝血因子ⅩⅢa能够轻易地在vWF中的谷氨酰胺和纤维蛋白α链中的赖氨酸之间形成共价键。当血浆凝血缓慢时，此反应在体外容易发生，并且在类似条件下可能在体内发生。
