Dahlbäck B
J Biol Chem. 1986 Jul 15;261(20):9495-501.
Single chain bovine factor V (Mr = 330,000) was isolated and visualized by means of high resolution transmission electron microscopy of negatively stained samples. Both factor Va, activated by thrombin or by the factor V activator from Russell's viper venom, and the isolated fragments, D (Mr = 105,000), C1 (Mr = 150,000), and F1F2 (Mr = 72,000), were studied. Single chain factor V appeared as a multidomain structure with three globular domains of similar size (diameter approximately 80 A), and oriented around a somewhat larger central domain (diameter approximately 140 A). The distance between the center of the molecule and the center of each of the peripheral domains was 120 A and the maximum length of factor V was 300 A. The structure was essentially identical with that recently shown for human single chain factor V (Dahlbäck, B. (1985) J. Biol. Chem. 260, 1347-1349). Isolated thrombin-activated factor Va (containing fragments D and F1F2) was composed of two domains of similar size, each of which was approximately 80 A in diameter and corresponded in size and shape to the peripheral domains seen in intact factor V. The isolated activation fragment C1 appeared as an irregular structure with an approximate diameter of 140 A and corresponded in size and shape to the larger central domain in intact factor V. The activator from Russell's viper venom only cleaves the bond(s) between C1 and F1F2, which results in two fragments, a larger fragment (Mr = 220,000) bearing the D, E, and C1 region and a smaller one corresponding to the F1F2 fragment. The venom-activated factor Va in the electron microscope demonstrated a multidomain structure similar in size and shape to that obtained with intact factor V. A model for factor V and the molecular events involved in activation is proposed.
单链牛凝血因子V（Mr = 330,000）通过对负染样品进行高分辨率透射电子显微镜观察进行分离和可视化。研究了经凝血酶或来自锯鳞蝰蛇毒的凝血因子V激活剂激活的凝血因子Va以及分离出的片段D（Mr = 105,000）、C1（Mr = 150,000）和F1F2（Mr = 72,000）。单链凝血因子V呈现为一种多结构域结构，具有三个大小相似的球形结构域（直径约80 Å），围绕一个稍大的中央结构域（直径约140 Å）排列。分子中心与每个外围结构域中心之间的距离为120 Å，凝血因子V的最大长度为300 Å。该结构与最近报道的人单链凝血因子V的结构基本相同（达尔贝克，B.（1985年）《生物化学杂志》260，1347 - 1349）。分离出的经凝血酶激活的凝血因子Va（包含片段D和F1F2）由两个大小相似的结构域组成，每个结构域直径约80 Å，其大小和形状与完整凝血因子V中的外围结构域相对应。分离出的激活片段C1呈现为不规则结构，直径约140 Å，其大小和形状与完整凝血因子V中较大的中央结构域相对应。来自锯鳞蝰蛇毒的激活剂仅切割C1和F1F2之间的键，产生两个片段，一个较大的片段（Mr = 220,000）带有D、E和C1区域，另一个较小的片段对应于F1F2片段。电子显微镜下的蛇毒激活的凝血因子Va呈现出一种多结构域结构，其大小和形状与完整凝血因子V的相似。本文提出了凝血因子V及其激活过程中涉及的分子事件的模型。
