H0393 Sigma

Hirudin from leeches

recombinant, expressed in unspecified host, ≥7,000 ATU/mg protein (ATU = antithrombin units)



Analysis Note

Protein determined by Lowry.


Hirudin is soluble in water. The literature cites the use of "Dilution Fluid II" (35.7 mM acetic acid, 35.7 mM sodium diethyl barbiturate, 0.85% NaCl, 1% bovine serum albumin, and 0.5% PEG, pH 7.4) to dissolve hirudin (500 ATU/mL) and thrombin. Hirudin is reported to be soluble in pyridine, but practically insoluble in alcohol, ether, acetone, or benzene.

Unit Definition

One antithrombin unit (ATU) will neutralize one NIH unit of thrombin at 37 °C, based on direct comparison to an NIH thrombin reference standard.


Antithrombotic efficacy by parenteral route is substantially prolonged by incorporation into cationic liposomes, which act as a sort of sustained-release device.

Physical properties

The anticoagulant hirudin is a ~7 kDa acidic protein containing 65 amino acid residues. It is the most potent natural inhibitor of both soluble and clot-bound thrombin. Hirudin binds thrombin with high affinity and covers more than 20% of the surface area of thrombin, occluding both the active site and exosite I (fibrinogen and PAR recognition site). This coverage blocks thrombus growth and platelet activation. Hirudin is not metabolized in the bloodstream of humans and is eliminated unchanged via kidney filtration. Native hirudin contains a sulfated tyrosyl residue (Tyr63), three disulfide bridges, and a high proportion of dicarboxylic acids. Hirudin is not glycosylated, and lacks tryptophan, arginine, and methionine residues. At least 20 isoforms have been identified and sequenced.

This product corresponds to the HV-1 variant sequence, with the exception that the Tyr63 residue is not sulfated.

Price and Availability

All labs need water

Biomedical Applications
Safety & Documentation

Safety Information

Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 


Certificate of Analysis

Certificate of Origin

Protocols & Articles


Plasma Derived Proteins and Enzymes

Despite their complexity, blood and plasma are abundant biological resources for the discovery of drug targets and biomarkers for human disease. It is estimated that plasma may contain as many as 40,...
BioFiles 2006, 1.5, 2.
Keywords: Applications, Gas chromatography, Type

Peer-Reviewed Papers


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