You are here:HOME>News>Export>Proteinase K

Proteinase K

Time:2020-05-21 Hits:3743


Proteinase K, produced by the fungus Tritirachium album Limber, is a serine protease that exhibits a very broad cleavage specificity. It cleaves peptide bonds adjacent to the carboxylic group of aliphatic and aromatic amino acids and is useful for general digestion of protein in biological samples . It has been purified to be free of RNase and DNase activities. The stability of Proteinase K in urea and SDS and its ability to digest native proteins make it useful for a variety of applications.


Mitochondria isolation

Protein digestion for nucleic acid (DNA and RNA) purification

Removal of endotoxins bound to cationic proteins, such as lysozyme and ribonuclease A

Determination of enzyme localization on membranes

Exposure of antigen binding sites on paraffin embedded tissue sections for antibody labeling

Removal nucleases for in situ hybridization

Digestion of proteins from brain tissue samples

Protease footprinting to reveal protein-protein surface interactions


Catalog No.


Product Name

Proteinase K


Tritirachium album limber


White lyophilized powder


≥30U/mg protein

Molecular Weight




EC No.

Unit Definitions

One unit is defined as the amount of enzyme that 
will liberate 1 μmol of tyrosine per minute at 37º C, pH7.5.

DNase residue

Not detectable with λ DNA after 6 hours incubation at 37ºC.

RNase residue

Not detectable in up to 40 μg after 16 hours incubation at +25°C.。


Proteinase K is inhibited by diisopropyl fluorophosphate and 
phenylmethylsulfonyl fluoride (PMSF) and is also totally 
inactivated by mercuric ions.




Proteinase K is supplied as a lyophilized powder. Reconstitute in 50mM Tris-HCl (pH 8.0), 2mM CaCl 2 .

Storage Conditions:

See the Product Information Label for storage recommendations. The lyophilized powder should be stored desiccated. The reconstituted protease should be stored at –20°C, where it is stable for 2–3 months. Avoid multiple freeze-thaw cycles or exposure to frequent temperature changes. These fluctuations can greatly alter product stability. It is best to prepare proteases just prior to use or aliquot and freeze at –20°C.

Experimental data

Purity & Function Assay(SDS-PAGE)

Conclusion: Proteinase K purity99%

Stability Data


1. Kraus, E; Proteinase K from the Mold Tritirachium album limber, Specificity and Mode of Action. Z. Physiol. Chem., 357:939; 1976.

2.  Jany,KD, et al. Amino Acid Sequence of Proteinase K from the Mold, Tritirachium album limber. Proteinase K; a Subtilisin-related Enzyme with Disulfide Bonds. FEBS Letter, 199,139.1986.

3.  Sambrook, J., Fritsch, E.F. and Maniatis, T. (1989) Molecular Cloning: A Laboratory Manual, Volume 3, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, B.16.

4. Sweeney, P.J. and Walker, J.M. (1993) Enzymes of molecular biology. In: Methods in Molecular Biology, Vol. 16, M.M. Burrell, ed., Humana Press, Inc., Totowa, NJ, 305.

Attention for product acceptance and operation:

1. In strict accordance with the technical requirements of nucleic acid detection experiment, the operation shall be carried out under sterile conditions, the relevant instruments and reagents used shall meet the requirements of no DNA enzyme / RNA enzyme residue to prevent pollution

2. All the large package (not less than 100g package) delivered by our company are sent with the same batch small package samples (100mg / piece * 3) .The samples are for the quality acceptance or test when the customer receives the goods.

Special note: please test the small sample within 5 working days after receiving the goods, and open the large package for formal use after the small sample passes the test (if the quality does not meet the specifications marked on the label / COA, or the small sample quality is not recognized, the large package cannot be unpacked absolutely; and please gives the feedback to our company with written document at the same day for communication and handling). Once the large package is unpacked, it will be regarded as approving the product quality and not accepting the product objection treatment (unless the test results of large and small packages are different and do not meet the specifications on COA);

3. After opening the package, if it needs to be subpacked, please make sure to be accordance with the 1st  operation to avoid secondary pollution. We are not responsible for the quality problems caused by the secondary pollution of the receiving party.

4. For each product we send out, the same batch samples(100mg / piece * 3) is retained by ourselves.