site map  

 

 

 

 

 

 

 


QUESTIONS?

+1 (802) 878-1777

hti@haemtech.com


 

 

 

 

 

 

 

 

ORDERING

Human Proteins

Bovine Proteins

Mouse Proteins

Other Species

Inhibitors

Substrates

Antibodies

Sample Collection Tubes

Deficient Plasmas

Assay Kits

Pricing

HOME PAGE

 

 

 

 

 

 

 

 

QUESTIONS?

+1 (802) 878-1777

hti@haemtech.com

α2-Plasmin Inhibitor

a2Plasmin Inhibitor and Fibrinolysis. The primary physiological inhibitor of plasmin is a2plasmin inhibitor. The binding of a2 –plasmin inhibitor to plasmin(ogen) plays a critical role in fibrinolysis. The binding of circulating free plasmin(ogen) by a2 –plasmin inhibitor prevents both zymogen and enzyme from binding to fibrin and ultimately initiating fibrinolysis. a2Plasmin inhibitor already crosslinked to fibrin prevents plasmin catalytic action on local sites of fibrin deposition as well as impeding subsequent activation of plasminogen via plasminogen activator.

PURCHASING AND PRODUCT INFORMATION

 

Catalog Number

HA2AP-0230

Description

α2 –Plasmin Inhibitor

Size

100 µg

Formulation

50 KPO4, 7.5 mM KCl, 75 uM EDTApH 7.4

Storage

-80oC

Purity

>95% by SDS-PAGE

Activity Determination

Plasmin inhibition assay

Shelf Life (properly stored)

12 months

Sample Gel Information:

Gel: Novex 4-12% Bis-Tris

Load: Human α2 –Plasmin Inhibitor, 1 µg per lane

Buffer: MOPS

Standard: SeeBluePlus 2; Myosin (191 kDa), Phosphorylase B (97 kDa), BSA (64 kDa), Glutamic Dehydrogenase (51 kDa), Alcohol Dehydrogenase (39 kDa), Carbonic Anhydrase (28 kDa), Myoglobin Red (19 kDa), Lysozyme (14 kDa)

 

Sample publications referencing our alpha-2 antiplasmin:

  1. Tseng, I., et al., Am J Physiol Cell Physiol 295:423-431, 2008.

This publication list is not all encompassing, and is only meant to provide limited examples of how Haematologic Technologies' products are used.  We encourage you to search the literature for other examples pertinent to your experimentation, and to contact us with any technical questions.

U.S. Pricing

Product inquiry

SAMPLE DATA SHEET

ORDER NOW!

 

Overview of α2 –plasmin inhibitor

α2 –plasmin inhibitor (α2 -PI) is a single-chain glycoprotein and is one of the major serine proteinase inhibitors circulating in plasma. Physiologically, it is the predominant inhibitor of plasmin and it therefore plays a significant role in the specific inhibition of fibrinolysis. The role of α2 -PI in fibrinolysis is three fold: covalent inhibition of plasmin; interference with the binding of plasminogen to fibrin; and factor XIIIa catalyzed cross-linking of α2-PI to fibrin (1). Rapid inactivation of plasmin proteolytic activity occurs through a two-step process. The inhibitor first forms a reversible complex with plasmin which is sub-sequently followed by the formation of a covalent, enzymatically inactive, complex with the catalytic site in plasmin (2,3). α2-PI also functions by interfering with the binding of plasminogen to fibrin, effectively slowing the activation of plasminogen by fibrin-bound plasminogen activator (4). The interference in binding ultimately delays the initiation of fibrinolysis. Covalent cross-linking of a2-PI to the a-chains of fibrin which is mediated by factor XIIIa, protects crosslinked fibrin clots from plasmin degradation and thereby markedly stabilizes the fibrin clot against fibrinolysis (5). Failure to protect the fibrin clot from rapid dissolution before injured vessels can be restored results in a bleeding tendency described in patients with a deficiency in α2-PI or factor XIII (6,7).

The structure of α2-PI consists of three functionally important regions. A reactive site is located at Arg-364 that forms a covalent bond with the plasmin active site (8). A high affinity plasminogen-binding site located within the last 20 COOH-terminal amino acids is responsible for binding the NH2 -terminal kringle structures of plasmin(ogen) (4). An endogenous partially degraded form (non-plasminogen-binding form) of α2-PI lacking this COOH-terminal region makes up about 30% of the circulating α2-PI found in normal plasma (9). Lastly, the cross-linking site in α2-PI is located in the NH2 -terminal part of the molecule at Gln-2 (10).

α2–plasmin inhibitor is prepared from fresh frozen plasma by a combination of ion exchange, affinity, and gel filtration chromatography steps. Our purification selects exclusively for the native plasminogen-binding form. Purified α2 –plasmin inhibitor is supplied in 50 mM potassium phosphate, 7.5 mM KCl, 0.075 mM EDTA, pH 7.4 and should be stored at -70°C. Purity is assessed by SDS-PAGE analysis and plasmin inhibition assay.

Properties of α2 –plasmin inhibitor

Localization Plasma
Mode of action: Inhibits plasmin by forming an irreversible complex with the catalytic active site.  Prevents the binding of plasmin to fibrin.  Cross-linked by factor XIIIa to fibrin.
Plasma Concentration: 69 µg/ml (1)
Molecular weight: 58,700 single-chain (determined from amino acid sequence and 14% carbohydrate) and 67,000 (determined by SDS-PAGE) (1)
Extinction coefficient:
E
1 %
1 c m, 280 nm
= 7.03 (2)
Isoelectric Point: Unknown
Structure: Circulates as single chain molecule consisting of 452 amino acids (1).
Percent carbohydrate: 14% (w/w) (1)

References 
1. Aoki, N. et al., Methods Enzymol., 223, 185-197 (1993).
2. Moroi, M. and Aoki, N., J. Biol. Chem., 251, 5956 (1976).
3. Wiman, B. and Collen, D., J. Biol. Chem., 254, 9291 (1979).
4. Moroi, M. and Aoki, N., Thromb. Res., 10, 851 (1977).
5. Sakata, Y. and Aoki, N., J. Clin. Invest., 69, 536 (1982).
6. Aoki, N. et al., J. Clin. Invest., 63, 877 (1979).
7. Israels, E. D. et al., J. Clin. Invest., 52, 2398 (1973).
8. Holmes, W. E. et al., J. Biol. Chem., 262, 1659 (1987).
9. Kluft, C. and Los, N., Thromb. Res., 21, 65 (1981).
10. Tamaki, T. and Aoki, N., J. Biol. Chem., 257, 14767 (1982).

 

PRODUCTS ORDERING SERVICES ABOUT US TECH NOTES CONTACT

 

© 2009 Haematologic Technologies, Inc. All Rights Reservedspacer