A6103 Sigma-Aldrich

Aprotinin bovine

recombinant, expressed in Nicotiana (tobacco), ≥5 TIU/mg protein, ≥98% (SDS-PAGE)



Related Categories Analytical and Industrial Enzymes, Biochemicals and Reagents, Enzyme Inhibitors, Enzyme Inhibitors by Type, Enzymes, Inhibitors, and Substrates,
Quality Level   300
biological source   bovine
recombinant   expressed in Nicotiana (tobacco)
product line   BioUltra
assay   ≥98% (SDS-PAGE)
form   powder
specific activity   ≥5 TIU/mg protein
mol wt   ~_6.5 kDa
application(s)   inhibition assay: suitable
solubility   0.85% sodium chloride: 5 mg/mL
storage temp.   2-8°C
Gene Information   cow ... PTI(404172)



1, 25, 100 mg in glass bottle

Biochem/physiol Actions

Aprotinin is a competitive serine protease inhibitor that inhibits trypsin, chymotrypsin, kallikrein and plasmin. It had earned a place as an antiinflammatory and antithrombotic adjunct to cardiac surgery, but its value has been called into question.Aprotinin forms stable complexes with and blocks the active sites of enzymes. Binding is reversible with most aprotinin-protease complexes dissociating at pH >10 or <3. Effective concentration equimolar with protease.

Unit Definition

One trypsin inhibitor unit (TIU) will decrease the activity of 2 trypsin units by 50% where one trypsin unit will hydrolyze 1.0 μmole of N-α-benzoyl-DL-arginine p-nitroanilide (BAPNA) per min at pH 7.8 at 25 °C.

Preparation Note

Aprotinin is freely soluble in water (>10 mg/ml) and in aqueous buffers of low ionic strengths. Dilute solutions are generally less stable than concentrated ones. Solution stability is pH dependent; a range of 1-12 can be tolerated. Repeated freeze-thaw cycles should be avoided. Due to its compact tertiary structure, aprotinin is relatively stable against denatura­tion due to high temperature, pH extremes, organic solvents, or proteolytic degradation (only thermolysin has been found capable of degrading aprotinin after heating to 60-80 °C). The high basicity of aprotinin causes it to adhere to commonly used dialysis tubing and even gel filtration matrices, but the use of acetylated materials and concentrated salt solutions (=0.1 M NaCl in buffer) minimizes the problem. Sterilization may be achieved by filtration through a 0.2 μm filter.

Contains no animal-derived components or impurities, and is manufactured by transient expression of the aprotinin message in RNA (+)-strand tobacco mosaic virus vectors propagated in non-transgenic Nicotiana plants. This is a recombinant form of the native, bovine-sequence aprotinin, which is traditionally isolated from bovine lung by methods involving fractional precipitation, gel filtration, and ion exchange chromatography. Unlike animal-derived aprotinin, this product is isolated and purified from plant tissue by proprietary methods.

Safety & Documentation

Safety Information

Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 
Flash Point(F) 
Not applicable
Flash Point(C) 
Not applicable


Certificate of Analysis (COA)

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Certificate of Origin (COO)

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Frequently Asked Questions

How does the storage temperature relate to shipping conditions?
The storage conditions that a Sigma-Aldrich catalog and label recommend for products are deliberately conservative. For many products, long-term storage at low temperatures will increase the time during which they are expected to remain in specification and therefore are labeled accordingly. Where short-term storage, shipping time frame, or exposure to conditions other than those recommended for long-term storage will not affect product quality, Sigma-Aldrich will ship at ambient temperature. The products sensitive to short-term exposure to conditions other than their recommended long-term storage are shipped on wet or dry ice. Ambient temperature shipping helps to control shipping costs for our customers. At any time, our customers can request wet- or dry-ice shipment, but the special handling is at customer expense if our product history indicates that the product is stable for regular shipment. See Shipping and Storage for more information.
Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.
How do I get lot-specific information or a Certificate of Analysis?
The lot specific COA document can be found by entering the lot number above under the "Documents" section.
How do I find price and availability?
There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote. USA customers: 1-800-325-3010 or view local office numbers.
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.
How doesProduct A6103, Aprotinin bovine, compare to Trasylol?
Trasylol is the Bayer AG registered trademark name for this material.
Do you assay thisthe activity of Product A6103, Aprotinin bovine,in TIU or in KIU?
We express the product's activity in TIU (Trypsin Inhibitor Units). Multiply the activity on the Certificate of Analysis by 1300 to convert it to KIU (Kallikrein Inhibitor Units).
How should I store solutions of Product A6103, Aprotinin bovine?
We generally advise storing stock solutions of approximately 5-10 mg/mL. Working solutions down to 0.065 micrograms/mL can be stored refrigerated at 2-8°C for one week, or at - 20°C for appoximately six months in single use aliquots. See Table 2 in the Datasheet for details.
At what concentration should I use Product A6103, Aprotinin bovine?
For most applications, 10 to 800 nM works well (based on a molecular weight of 6512 g/mol). This information may be found in the technical bulletin for the Protease Inhibitor Panel, Product No. INHIB1.
Product A6103, recombinant bovine aprotinin has a specification of ~60% protein. What is the remaining components of the solid?
Product A6103, recombinant bovine aprotinin is >98% purity by SDS-PAGE. The product is ~60% protein with the balance being salts (NaCl).
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Protocols & Articles


Enzymatic Assay of Aprotinin

The scope of this procedure is all products that have a specification for Aprotinin activity.
Keywords: Enzymology, Extinction coefficient

Peer-Reviewed Papers


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