Pusey M L, Mende T J
Thromb Res. 1985 Sep 1;39(5):571-85. doi: 10.1016/0049-3848(85)90237-3.
Partially purified Amniotic Fluid Factor (AFF) is found to directly activate human factor X, with a Km for factor X of 0.37 +/- 0.06 M. Added phospholipid has only a slight effect on the activation at low concentrations, and inhibits the reaction at higher concentrations. Both DIPF and PMSF inhibit AFF factor X activation. Although added phospholipid is not required for AFF-activity, phospholipase C rapidly destroys it, indicating the presence of intrinsic phospholipid. Phospholipase C treated AFF releases factor VII activity, which leads to the conclusion that AFF is in fact a thromboplastin: factor VII complex. Both AFF and a human brain thromboplastin factor VII complex prepared in vitro were inhibited by Zn++ ion, while human brain thromboplastin alone is not. AFF is markedly larger than the human brain thromboplastin-factor VII complex as judged by gel filtration.
部分纯化的羊水因子（AFF）被发现可直接激活人因子X，其对因子X的米氏常数（Km）为0.37±0.06M。添加的磷脂在低浓度时对激活仅有轻微影响，而在高浓度时则抑制该反应。二异丙基氟磷酸（DIPF）和苯甲基磺酰氟（PMSF）均抑制AFF对因子X的激活。尽管AFF的活性不需要添加磷脂，但磷脂酶C能迅速破坏它，这表明存在内在磷脂。经磷脂酶C处理的AFF释放出因子VII活性，由此得出结论，AFF实际上是一种凝血活酶：因子VII复合物。AFF和体外制备的人脑凝血活酶因子VII复合物均被Zn++离子抑制，而单独的人脑凝血活酶则不受抑制。通过凝胶过滤判断，AFF明显大于人脑凝血活酶 - 因子VII复合物。
