Greenquist A C, Weinberg R M, Kuo A L, Colman R W
Eur J Biochem. 1975 Oct 1;58(1):213-22. doi: 10.1111/j.1432-1033.1975.tb02366.x.
Native bovine factor V exhibits a molecular weight of 300000 as determined by gel filtration of untreated plasma. Highly purified factor V exhibits multiple molecular weight forms which range from small active fragments to aggregates of several million which are generated during the purification on cellulose phosphate. Isoelectric focusing on a single high-molecular-weight species produced a single protein and activity peak at pH 4.65. Factor V activity is associated with each protein band observed following polyacrylamide gel electrophoresis. Antisera to factor V prepared in rabbits produces a time-dependent and concentration-dependent inhibition of factor V activity in plasma and purified factor V. The multiple molecular weight forms of factor V appear equivalent upon immunodiffusion and on immunoelectrophoresis migrate as an alpha globulin between albumin and fibrinogen. Immunoprecipitation arcs are equivalent in plasma and serum. Factor V consists of two major types of subunits, a light chain (73000), aggregates of which form the high-molecular-weight species, and a heavy chain (125 000). Using preparations containing one or both chains isolated by disc gel electrophoresis, antiserum was shown to contain two families of antibodies, one against each subunit. Cross reactivity with both light and heavy chain antigens is observed in sheep and goat but not monkey or human plasma. The antisera also neutralized goat and sheep factor V activity.
通过对未经处理的血浆进行凝胶过滤测定，天然牛因子V的分子量为300000。高度纯化的因子V呈现出多种分子量形式，范围从小的活性片段到在磷酸纤维素纯化过程中产生的数百万的聚集体。对单一高分子量物种进行等电聚焦，在pH 4.65处产生了一个单一的蛋白质和活性峰。在聚丙烯酰胺凝胶电泳后观察到的每条蛋白质带都与因子V活性相关。用兔制备的抗因子V血清对血浆和纯化的因子V中的因子V活性产生时间依赖性和浓度依赖性抑制。因子V的多种分子量形式在免疫扩散时似乎是等效的，并且在免疫电泳中作为α球蛋白在白蛋白和纤维蛋白原之间迁移。血浆和血清中的免疫沉淀弧是等效的。因子V由两种主要类型的亚基组成，一条轻链（73000），其聚集体形成高分子量物种，还有一条重链（125000）。使用通过圆盘凝胶电泳分离的含有一条或两条链的制剂，显示抗血清含有两类抗体，一类针对每个亚基。在绵羊和山羊血浆中观察到与轻链和重链抗原的交叉反应，但在猴或人血浆中未观察到。该抗血清也中和了山羊和绵羊因子V的活性。
