Factor V, Human

Factor V is a large, single chain, plasma glycoprotein which is an essential component in the blood coagulation cascade (1). During coagulation, the procofactor, factor V, is converted to the active cofactor, factor Va, via limited proteolysis by the serine protease a-thrombin (illustrated above), and less efficiently by factor Xa. The active cofactor is composed of an NH2-terminal derived heavy chain (Mr=94,000) and a COOH-terminal derived light chain (Mr=74,000) which remain non-covalently associated in the presence of calcium ions. Factor Va serves as a cofactor for the serine protease factor Xa. Factor Va and Xa assemble on a phospholipid surface in a non-covalent and calcium ion-dependent manner, to form the prothrombinase complex. The prothrombinase complex is responsible for the rapid conversion of the zymogen prothrombin to the active serine protease, a-thrombin. Assembly of the prothrombinase complex increases the rate at which prothrombin is converted to thrombin by nearly 300,000-fold relative to the rate with factor Xa alone. Down regulation of the prothrombinase complex is accomplished partly through the inactivation of factor Va by activated protein C.\n\nStructure:\nOne subunit, 2196 amino acids\n\nActivity: \n~40 units/mg; Measured in a factor V clotting assay.\n\nUnit Definition:\nOne unit is equivalent to the Factor V activity in 1ml of normal human plasma.\n\nExtinction Coefficient (1%, 1cm, 280nm):\n9.6\n\nPost-translational Modifications:\n11gla residues, 1beta-hydroxyaspartate residue.\n\nFactor V Localization:\nPlasma and platelets\n\nMode of Action: \nProcofactor; activated by thrombin to form the active cofactor, factor Va

Prices direct from United States Biological

Quick response times

Exclusive Biosave savings/discounts

SPECIFICATIONS

Catalog Number

F0011-09

Size

50ug

Form

Supplied as a liquid in 50% glycerol, H2O.

Purity

~ 98%; SDS-PAGE. Purified by immunoaffinity chromatography.

References

1. Mann, K.G., et al., Ann. Rev. Biochem., 57: 915 (1988). 2. Katzmann, J.A., et al., Proc. Natl. Acad. Sci. USA, 78: 162 (1981). 3. Nesheim, M.E., et al., J. Biol. Chem., 254: 508 (1979).