Human blood clotting factor IX, and two chimeric molecules of factor IX, in which the first epidermal growth factor-like domain or both epidermal growth factor-like domains have been replaced by that of human factor X, have been expressed in mouse C127 cells. The recombinants have been purified using a metal ion-dependent monoclonal antibody specific for residues 1-42 of human factor IX. All re...

Human blood clotting factor IX, and two chimeric molecules of factor IX, in which the first epidermal growth factor-like domain or both epidermal growth factor-like domains have been replaced by that of human factor X, have been expressed in mouse Cl27 cells. The recombinants have been purified using a metal ion-dependent monoclonal antibody specific for residues l-42 of human factor IX. All re...

Cross-reacting factor IX material (CRM) was immunologically detected in the plasma of 38 normal individuals and 21 out of 22 haemophilia B patients using a rabbit antibody to factor IX. The same reacting material was detected in only nine of these patients using a human antibody. These results indicate that the plasma of the majority of haemophilia B patients contains a protein-lacking biologic...

As an approach to the study of structure-function relationships in the normal and defective forms of human coagulation factor IX, we have begun to develop a series of monoclonal antibodies against specific sites on the protein. Zymogen and activated forms of normal factor IX were used initially as antigen for the preparation of monoclonal antibodies. Recombinant phage were prepared by cloning s...

Currently available anticoagulants are limited by modest therapeutic benefits, narrow clinical applications, increased bleeding risk, and drug-induced thrombophilia. Because factor IX plays a pivotal role in thrombin generation, it may represent a promising target for drug development. Several methods of attenuating factor IX activity, including monoclonal antibodies, synthetic active site-bloc...

Thromb Haemost 2008; 99: 799–800 Developing effective cell-based therapies to treat severe haemophilia B remains attractive for several reasons. Ondemand and prophylactic factor IX replacement using plasma-derived or recombinant factor IX are both safe and effective (1). However, the cost of either replacement product for lifelong therapy is a significant barrier for patients with limited acces...

Recent investigations have suggested that the activation of factor IX by factor VII/tissue factor may be an important alternative route to the generation of factor Xa. Accordingly, we have compared the tissue factor-dependent activation of tritium-labeled factor IX and factor X in a human plasma system and have studied the role of proteases known to stimulate factor VII activity. Plasma was def...

Hemophilia B is a recessive bleeding disorder resulting from mutations in the coagulation factor IX gene. As this disease is characterized by clinical and molecular heterogeneity, the building of relationship between its genotype and phenotype would be great helpful for better diagnosis, prognosis and treatment. We use a descriptively probabilistic method, cross-impact analysis, to couple the c...

Human factor IX circulates as a single-chain glycoprotein. Upon activation in vitro, it is cleaved into disulfide-linked light and heavy chains and an activation peptide. After reduction of activated 125I-factor IX, the heavy and light chains are readily identified by gel electrophoresis. A direct, immunoradiometric assay for factor IXa was developed to assess activation of factor IX for protea...