Tazi S, Tans G, Hemker H C, Nigretto J M
Laboratoire de Chimie Bioanalytique, Université de Tours, France.
Thromb Res. 1992 Sep 15;67(6):665-76. doi: 10.1016/0049-3848(92)90070-q.
We prepared a derivative of dextran T40 (average M(r) 43,000) from which fractions of different M(r) but with equal charge density were obtained and tested for their ability to promote autoactivation of human blood coagulation factor XII. The mechanism of autoactivation appeared dependent upon the M(r) of the polymer used. Thus, with polymers of 38,000 M(r) or higher only alpha-factor XIIa was formed and the reaction could be completely described in terms of a simple second-order mechanism of autoactivation. With smaller polymer molecules beta-factor XIIa became a major reaction product and as a result of this the autoactivation kinetics did not adhere to the second-order mechanisms thus far described.
我们制备了葡聚糖T40（平均分子量43,000）的衍生物，从中获得了不同分子量但电荷密度相等的级分，并测试了它们促进人凝血因子XII自激活的能力。自激活机制似乎取决于所用聚合物的分子量。因此，对于分子量为38,000或更高的聚合物，仅形成α-因子XIIa，并且该反应可以用简单的二级自激活机制完全描述。对于较小的聚合物分子，β-因子XIIa成为主要反应产物，因此自激活动力学不符合迄今为止所描述的二级机制。
