Antibodies to Alpha 2-Antiplasmin

Alpha 2 -Antiplasmin, human

Antibody Host Catalogue No. Size Product Insert
purified IgG Goat GA2AP-IG 5 mg
affinity purified IgG Goat GA2AP-AP 0.5 mg
peroxidase conjugated IgG Goat GA2AP-HRP 0.2 mg
purified IgG Sheep SA2AP-IG 10 mg

Description of Alpha 2-Antiplasmin

Alpha 2-Antiplasmin (α2AP), also known as Alpha 2-Plasmin Inhibitor (α2PI), is a member of the SERPIN family of proteinase inhibitors and the primary inhibitor of the enzyme plasmin in blood. It is produced in the liver and circulates in plasma at ~70 μg/ml (~1 μM). α2AP is a single chain molecule with a mass of 67 kDa as determined by SDS-PAGE. The primary target enzyme for α2AP is plasmin, but α2AP also acts as secondary or “backup” inhibitor of activated FXI, activated Protein C and trypsin. Inhibition of these enzymes by α2AP occurs through proteolytic cleavage after Arg364 with subsequent rapid formation of a stable, inactive 1:1 enzyme-α2AP complex. α2AP also acts to regulate fibrinolysis by binding to the lysine binding sites on plasminogen thus competitively inhibiting plasminogen binding to fibrin. About 30% of α2AP present in plasma is partially degraded and lacks a peptide in the carboxyl region that contains the plasminogen-binding site. This form of α2AP (~65 kDa) has a reduced rate of plasmin inhibition and has been referred to as the “slow form” of α2AP. During fibrin formation, a portion of circulating α2AP is cross-linked to the α-chain of fibrin by activated factor XIII, and this linking of plasmin inhibitor to the plasmin substrate provides an additional measure of protection to the fibrin clot from proteolysis by plasmin1-4.


1. Aoki N, Suni Y, Miura O, Hirosawa S; Human α2Plasmin Inhibitor; Methods in Enzymology, 223, pp 185-197, 1993.

2. Shieh BH, Travis J; The Reactive Site of Human α2-Plasmin Inhibitor ; JBC 262, pp 6055-6059, 1987.

3. Moroi M, Aoki N; Isolation and Characterization of α2-Plasmin Inhibitor from Human Plasma; JBC 251, pp 5956-5965, 1976.

4. 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.

Related Products:

GA2AP-IG Goat anti-human α2AP, whole IgG from antiserum

GA2AP-AP Goat anti-human α2AP, affinity purified IgG

GA2AP-HRP Goat anti-human α2AP, APIgG-peroxidase conjugate

SA2AP-AP Sheep anti-human α2AP, affinity purified IgG

A2AP-DP Plasma deficient in Alpha 2-Antiplasmin, immune-depleted, Frozen
A2AP-LDP Plasma deficient in Alpha 2-Antiplasmin, immune-depleted, Lyophilized