Activation of coagulation leads to the generation of thrombin which, in the presence of thrombomodulin, will activate Protein C to the enzyme activated Protein C (APC). Unless regulated, APC will exert its anticoagulant function through proteolytic inactivation of factor Va and factor VIIIa. In blood, the activity of APC is regulated in part through interaction with protease inhibitors to form inactive enzyme- inhibitor complexes. Based on physiological concentrations and the kinetics of inhibition, the primary inhibitor of APC in blood is Protein C Inhibitor (PCI, also known as plasminogen activator inhibitor-3), followed by alpha-1 antitrypsin (alpha-1AT, also known as alpha-1proteinase inhibitor) and alpha-2 macroglobulin.
The APC-PCI complex (APC-PCI) results when APC cleaves a scissile bond near the C-terminus of PCI, forming a covalent 1:1 acyl- enzyme intermediate with PCI with an apparent mass of 110 kD. Calcium is not required for this interaction, but the rate of APC inhibition by PCI can be accelerated 50-fold by optimal concentrations of heparin. APC-PCI complex is cleared from circulation with a half-life of 19 minutes, presumably by serpin-enzyme complex receptors on the surface of hepatocytes.
Antibodies for 5x96 well plates
Capture Antibody: Affinity-purified, polyclonal anti-human Protein C antibody. Used to coat ELISA plates.
1 x 500ul (Yellow capped tube)
Detection Antibody: Polyclonal anti-human PCI antibody labeled with HRP. Used for detection of captured APC-PCI complex.
1 x 500ul (Red capped tube)
Storage and Stability:
May be stored at 4 degrees C for short-term only. For long-term storage, aliquot and store at -20 degrees C. Aliquots are stable for at least 6 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.