Factor IX

Amplification factor IX Calorie, international steam calj-j... 

Factor IX complex treatment of hemophilia B and other coagulation 57 5 X 10-"... 

Affinity chromatography is used in the preparation of more highly purified Factor IX concentrates (53—55) as well as in the preparation of products such as antithrombin III [9000-94-6] (56,57). Heparin [9005-49-6], a sulfated polysaccharide (58), is the ligand used most commonly in these appHcations because it possesses specific binding sites for a number of plasma proteins (59,60). 

Immunoaffinity chromatography utilizes the high specificity of antigen—antibody interactions to achieve a separation. The procedure typically involves the binding, to a soHd phase, of a mouse monoclonal antibody which reacts either directly with the protein to be purified or with a closely associated protein which itself binds the product protein. The former approach has been appHed in the preparation of Factor VIII (43) and Factor IX (61) concentrates. The latter method has been used in the preparation of Factor VIII (42) by immobilization of a monoclonal antibody to von WiHebrand factor [109319-16-6] (62), a protein to which Factor VIII binds noncovalenfly. Further purification is necessary downstream of the immunoaffinity step to remove... 

Table 11. Properties of Factor VIII (Antihemophilic Factor) and Factor IX Concentrates...

Factor VII. This is a vitamin K-dependent serine protease that functions in the extrinsic coagulation pathway and catalyzes the activation of Factors IX and X. Factor VII is present constitutively in the surface membrane of pericytes and fibroblasts in the adventitia of blood vessels, vascular endothehum, and monocytes. It is a single-chain glycoprotein of approximately 50,000 daltons. 

Factor IX. This factor is dependent on the presence of vitamin K for its activity as a biologicaUy functional procoagulant glycoprotein. Factor IX is converted to its active form by XIa in the classic scheme of the intrinsic pathway. However, it can also be activated via interaction with Factor Xa or the complex Factor III plus Factor VII in the presence of calcium. 

Congenital deficiency of Factor IX results in hemophilia B, also known as Christmas disease, and is inherited in a sex-linked recessive manner. Instmctive is the fact that some female carriers are symptomatic. Combined deficiencies of Factors VIIFC and IX have been described. 

Table 4 contains products available for Factor VII, Factor VIIFC (hemophilia A), Factor IX, and von Willebrand protein deficiency. Table 5 fists miscellaneous hemostatics and thein proposed mechanisms of action. 

Figure 2.19 Organization of polypeptide chains into domains. Small protein molecules like the epidermal growth factor, EGF, comprise only one domain. Others, like the serine proteinase chymotrypsin, are arranged in two domains that are required to form a functional unit (see Chapter 11). Many of the proteins that are involved in blood coagulation and fibrinolysis, such as urokinase, factor IX, and plasminogen, have long polypeptide chains that comprise different combinations of domains homologous to EGF and serine proteinases and, in addition, calcium-binding domains and Kringle domains.

Manno CS, Pierce GF, Arrada VR et al (2006) Successful transduction of liver in hemophilia by AAV-Factor IX and limitations imposed by the host immune response. Nat Med 12(3) 342-347... 

Heparin is an important anticoagulant. It binds with factors IX and XI, but its most important interaction is with plasma antithrombin III (discussed in Chapter 51). Heparin can also bind specifically to lipoprotein lipase present in capillary walls, causing a release of this enzyme into the circulation. 

Figure 51-1. The pathways of blood coagulation. The intrinsic and extrinsic pathways are indicated. The events depicted below factor Xa are designated the final common pathway, culminating in the formation of cross-linked fibrin. New observations (dotted arrow) include the finding that complexes of tissue factor and factor Vila activate not only factor X (in the classic extrinsic pathway) but also factor IX in the intrinsic pathway, in addition, thrombin and factor Xa feedback-activate at the two sites indicated (dashed arrows). (PK, prekallikrein HK, HMW kininogen PL, phospholipids.) (Reproduced, with permission, from Roberts HR, Lozier JN New perspectives on the coagulation cascade. Hosp Pract [Off Ed] 1992Jan 27 97.)...

Factor XIa in the presence of activates factor IX (55 kDa, a zymogen containing vitamin K-dependent y-carboxyglutamate [Gla] residues see Chapter 45), to the serine protease, factor IXa. This in turn cleaves an Arg-Ile bond in factor X (56 kDa) to produce the two-chain serine protease, factor Xa. This latter reaction requires the assembly of components, called the tenase... 

Inherited deficiencies of the clotting system that result in bleeding are found in humans. The most common is deficiency of factor VIII, causing hemophilia A, an X chromosome-hnked disease that has played a major role in the history of the royal families of Europe. Hemophilia B is due to a deficiency of factor IX its clinical Feamres are almost identical to those of hemophilia A, but the conditions can be separated on the basis of specific assays that distinguish between the two factors. 

Factor IX 415 amino acids glycosylated modified residues Mammalian cells Treatment of Christmas disease Approved for sale Must be made in mammalian cells since glycosylation and conversion of first 12 glutamate residues to pyroglutamate essential for activity... 

Rubella Vaccine, Live Mumps Vaccine, rDNA Hepatitis B Vaccine, Oral Poliovirus Vaccine, Erythropoietin, and Factor IX etcetera. 

Ferric ion was immobilized on a Chelating Sepharose Fast Flow column preparatory to the separation of seven enkephalin-related phosphopep-tides.17 Non-phosphorylated peptides flowed through the column, and the bound fraction contained the product. The capacity of the column was found to be 23 pmol/mL by frontal elution analysis. Cupric ion was immobilized on Chelating Superose for the isolation of bovine serum albumin.18 Cupric ion was immobilized on a Pharmacia HiTrap column for the separation of Protein C from prothrombin, a separation that was used to model the subsequent apparently successful separation of Factor IX from prothrombin Factor IX activity of the eluate was, however, not checked.19 Imidazole was used as the displacement agent to recover p-galactosidase from unclarified homogenates injected onto a nickel-loaded IMAC column.20 Pretreatment with nucleases and cleaning in place between injections were required procedures. A sixfold purification factor was observed. 

Wu, H. and Bruley, D.F, Homologous Human Blood Protein Separation Using Immobilized Metal Affinity Chromatography Protein C Separation from Prothrombin with Application to the Separation of Factor IX and Prothrombin, Biotechnol. Prog., 15, 928, 1999. 

---