Factor X is a vitamin K-dependent protein zymogen which is synthesized in the liver and circulates in plasma as a two chain molecule linked by a disulfide bond (1,2). Prior to secretion into plasma, post-translational modifications produce 11 gamma-carboxyglutamic acid (gla) residues and a single b-hydroxyaspartic acid residue, which are located within the NH2-terminal light chain. The light chain also contains two epidermal growth factor (EGF) homology domains. The COOH-terminal heavy chain of factor X contains most of the carbohydrate moieties, as well as the latent serine protease domain. The activation of factor X is catalyzed by either the intrinsic factor Xase complex (factor IXa, factor VIIIa, cellular surface and calcium ions) or the extrinsic factor Xase complex (factor VIIa, tissue factor, cellular surface and calcium ions). Activation of human factor X by either complex results in cleavage at Arg52-Ile53 of the COOH-terminal heavy chain and subsequent release of a 52 amino acid activation glycopeptide. Factor Xa then serves as the enzyme component of the prothrombinase complex which is responsible for the rapid conversion of prothrombin to thrombin. The gla residues enable factor X/Xa to bind phospholipid (i.e. cell surfaces) in a calcium dependent manner; a requirement for assembly of the prothrombinase complex. The first EGF homology domain contains a Ca2+ binding site which acts as a hinge to fold the EGF and GLA domains towards each other (12). This region of the molecule is involved in the recognition of cellular binding domains.
Human factor X is isolated from fresh frozen human plasma by a combination of conventional techniques (3) and immunoaffinity chromatography (4). In addition to the standard human factor X preparation, Gla-domainless human factor X is also available. Bovine factor X is isolated from fresh bovine plasma using a modification of the procedure reported by Bajaj et al. (5,6). The purified zymogen is supplied in 50% (vol/vol) glycerol/H2O and should be stored at -20oC. Purity is determined by SDS-PAGE analysis and activity is measured in a factor X clotting assay.
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最好能说得具体点，小弟对此几乎一窍不通
谢谢
1. 粗纯：将制备抗体的血清或是腹水，细胞上清，直接用盐析法进行处理，这样可以将这些物质里面的其他杂质去掉，获得蛋白的成分，但是由于是粗纯，里面会混有大量的其他蛋白，这样获得的抗体，纯度较低，用于实验中背景比较高。
2.通用型纯化：用抗体结合蛋白Protein A，Protein G或者Protein L。因为不同来源的抗体和这些抗体结合蛋白的结合能力不同，所以需要根据抗体来源选择使用哪种抗体将诶和蛋白最好。对于有一些单链抗体，则多半使用protein L来进行纯化。经过抗体结合蛋白的亲和纯化后，溶液中基本只保留了抗体的成分，其他蛋白都去掉了，抗体纯度可以比较高。相对来说，这种方法是大规模抗体制备中，用得最多的纯化方法，很多抗体公司都采用这种方法来对抗体进行纯化。
3.特异型纯化：但是有些抗体，需要纯度特别高，特异性特别好，就不能简单采用上述两种方法进行纯化了。必须要通过将抗原固定制备成特异的亲和纯化柱，再纯化抗体。这个时候得到的就全是针对一种抗原的抗体了，特异性最好。当然，由于牵涉到抗原固定等操作，成本相应是最高的。
1. 粗纯：将制备抗体的血清或是腹水，细胞上清，直接用盐析法进行处理，这样可以将这些物质里面的其他杂质去掉，获得蛋白的成分，但是由于是粗纯，里面会混有大量的其他蛋白，这样获得的抗体，纯度较低，用于实验中背景比较高。
2.通用型纯化：用抗体结合蛋白Protein A，Protein G或者Protein L。因为不同来源的抗体和这些抗体结合蛋白的结合能力不同，所以需要根据抗体来源选择使用哪种抗体将诶和蛋白最好。对于有一些单链抗体，则多半使用protein L来进行纯化。经过抗体结合蛋白的亲和纯化后，溶液中基本只保留了抗体的成分，其他蛋白都去掉了，抗体纯度可以比较高。相对来说，这种方法是大规模抗体制备中，用得最多的纯化方法，很多抗体公司都采用这种方法来对抗体进行纯化。
3.特异型纯化：但是有些抗体，需要纯度特别高，特异性特别好，就不能简单采用上述两种方法进行纯化了。必须要通过将抗原固定制备成特异的亲和纯化柱，再纯化抗体。这个时候得到的就全是针对一种抗原的抗体了，特异性最好。当然，由于牵涉到抗原固定等操作，成本相应是最高的。
