FunctionFactor VIII, along with calcium and phospholipid, acts as a cofactor for factor IXa when it converts factor X to the activated form, factor Xa.
Involvement in diseaseDefects in F8 are the cause of hemophilia A (HEMA) [MIM:306700]. A disorder of blood coagulation characterized by a permanent tendency to hemorrhage. About 50% of patients have severe hemophilia resulting in frequent spontaneous bleeding into joints, muscles and internal organs. Less severe forms are characterized by bleeding after trauma or surgery. Note=Of particular interest for the understanding of the function of F8 is the category of CRM (cross-reacting material) positive patients (approximately 5%) that have considerable amount of F8 in their plasma (at least 30% of normal), but the protein is non-functional; i.e., the F8 activity is much less than the plasma protein level. CRM-reduced is another category of patients in which the F8C antigen and activity are reduced to approximately the same level. Most mutations are CRM negative, and probably affect the folding and stability of the protein.
Sequence similaritiesBelongs to the multicopper oxidase family. Contains 3 F5/8 type A domains. Contains 2 F5/8 type C domains. Contains 6 plastocyanin-like domains.
DomainDomain F5/8 type C 2 is responsible for phospholipid-binding and essential for factor VIII activity.
Post-translational modificationsSulfation on Tyr-1699 is essential for binding vWF.
The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
Real Time PCR
Use at an assay dependent dilution. Suitable for the analysis of chromatin immunoprecipitated DNA using Taqman® real time PCR.
Quantity provided for 200 reactions. Please see the protocol page for the instructions for this product.