Antibodies to Antithrombin – ATIII

Antithrombin – ATIII, human

Antibody Host Catalogue No. Size Product Insert
purified IgG Goat GAAT-IG 10 mg
affinity purified IgG Goat GAAT-AP 0.5 mg
purified IgG Sheep SAAT-IG 10 mg
affinity purified IgG Sheep SAAT-AP 0.5 mg
affinity purified, peroxidase conj. IgG Sheep SAAT-APHRP 0.1 mg
affinity purified, FITC conjugated IgG Sheep SAAT-APFTC 0.1 mg
affinity purified, biotinylated IgG Sheep SAAT-APBIO 0.1 mg
Matched Pair Antibodies
– For EIA of Antithrombin ATIII-EIA 5 plates
– For EIA of T-AT Complex TAT-EIA 5 plates
Matched Pair Inhibitor and Control Antibodies
– For Neutralization of Antithrombin AT-NU10 10 det.

Antithrombin (ATIII), murine

Antibody Host Catalogue No. Size Product Insert
Matched Pair Antibodies for EIA MATIII-EIA 4 plates

Description of Antithrombin (ATIII)

TAT paired antibodies

Antithrombin, also known as Antithrombin III (ATIII), is a member of the SERPIN family of proteinase inhibitors and the primary inhibitor of thrombin in plasma. It is produced in the liver and circulates in plasma at ~200 μg/ml (~3.5 μM). Antithrombin inhibits a broad spectrum of serine proteases including thrombin, activated forms of factor X, factor IX, factor XI, factor XII, as well as kallikrein, plasmin and urokinase. Enzyme inhibition by antithrombin occurs through proteolytic cleavage at Arg385-Ser386 and subsequent rapid formation of a stable, inactive 1:1 enzyme-antithrombin complex. Heparin has a profound accelerating effect on the inhibitory activity of antithrombin towards some enzymes. For example, the rate of inhibition of thrombin and activated factor X is increased 1000-fold in the presence of optimal concentrations of heparin, whereas heparin has relatively little effect on the inhibition rate of activated factor XI, activated factor XII and kallikrein. Antithrombin is a single chain molecule with a molecular weight of 59 kDa. Interaction with thrombin results in an SDS-stable thrombin-antithrombin complex of 96 kDa1-3.

References: 1. Damus PS, Rosenberg RD; Antithrombin – Heparin Cofactor; Methods in Enzymology 45, pp 653-669, 1976. 2. Harpel PC; Blood Proteolytic Enzyme Inhibitors: Their Role in Modulating Blood Coagulation and Fibrinolytic Enzyme Pathways; in Hemostasis and Thrombosis, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp. 738-747, J.B. Lippincott Co., Philadelphia PA, USA, 1982. 3. Griffith MJ, Noyes CM, Church FC; Reactive Site Peptide Structural Similarity between Heparin Cofactor II and Antithrombin III; JBC:260, pp 2218-2225, 1985.
Description of Thrombin-Antithrombin Complex (TAT)

The 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 α2macroglobulin. 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.

Resources:

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.

Related Products:

GAAT-AP Goat anti-ATIII, affinity-purified IgG

SAAT-IG Sheep anti-ATIII, whole IgG from antiserum

SAAT-AP Sheep anti-ATIII, affinity-purified IgG

SAAT-APHRP Sheep anti-ATIII, APIgG-peroxidase

ATIII-EIA Paired antibody set for ELISA of ATIII, 5 x 96 wells

TAT-EIA Paired antibody ELISA of Thrombin-ATIII complexes

AT-NU10 Paired antibody set for ATIII neutralization in plasma

ATIII-DP Human plasma deficient in ATIII, immune depleted, Frozen

ATIII-LDP Human plasma deficient in ATIII, immune depleted, Lyophilized
ATHC-DP Human ATIII & HCII deficient plasma, immune depleted, Frozen
ATHC-LDP Human ATIII & HCII deficient plasma, immune depleted, Lyophilized