Thrombin Antithrombin Complex ManufacturingThe activation of coagulation ultimately leads to the activation of prothrombin to the enzyme thrombin. Unless regulated, thrombin will act on its natural substrates that include fibrinogen, factor V, factor VIII, factor XIII, Protein C, TAFI as well as specific receptors on platelets and endothelial cells. The activity of thrombin in plasma is regulated in part through interaction with protease inhibitors. Based on kinetic rates and physiological concentrations, the primary inhibitor of thrombin in plasma is antithrombin (ATIII), followed by heparin cofactor II and Î±2macroglobulin. The thrombin-antithrombin complex (TAT) results when thrombin cleaves a scissile bond near the C-terminus of ATIII, forming a covalent, 1:1 acyl enzyme intermediate with ATIII with an apparent mass of 96 kDa. Calcium is not required for this interaction, but the rate of thrombin inhibition by ATIII can be accelerated 1000-fold by optimal concentrations of heparin. Although TAT complex is relatively stable, under conditions of elevated pH and/or enzyme excess, enzymatic degradation and even dissociation of the complex can occur. In serum, vitronectin (also known as S-Protein) has been reported to form larger ternary complexes with TAT (350 kDa), but these ternary S-TAT complexes are not covalently linked and are not stable to denaturants such as SDS. T-AT complex is cleared from circulation by serpin-enzyme complex receptors on the surface of hepatocytes, with a half-life of 15 minutes1-4.
1. Bauer KA; Laboratory Markers of Coagulation Activation; Arch Pathol Lab Med 117, pp 71-77, 1993. 2. Pelzer H, Schwarz A, Heimburger N; Determination of Thrombin-Antithrombin Complexes in Plasma with an Enzyme-Linked Immunosorbent Assay; Thrombosis and Haemostasis 59, pp 101-106, 1988. 3. Griffith MJ, Lunblad RL; Dissociation of Antithrombin III-Thrombin Complex. Formation of Active and Inactive Antithrombin III; Biochemistry 20, pp 105, 1981. 4. Preissner KT, Zwicker L, Muller-Berghaus G; Formation, characterization and detection of a ternary complex between S protein, thrombin and antithrombin III in serum; Biochem. J. 243, pp 105-111, 1987.
|Antibody||Catalogue No.||Size||Product Insert|
|Matched Pair Antibodies for EIA||TAT-EIA||4 plates|