Proteinase K

Index Size
RP100B 100 mg
RP101B 250 mg
RP102B 1000 mg
RP105B 1 ml (10 mg/ml)
RP107B 1 ml (20 mg/ml)

Product Features

Mutagen and recombinant Proteinase K from Tritirachium album is non-specific, subtilisin-related serine protease [1] with a very high specific activity. The enzyme cleaves peptide bonds at the carboxylic sides of aliphatic, aromatic or hydrophobic amino acids. The smallest peptide to be hydrolyzed by this enzyme is a tetrapeptide. Proteinase K is supplied as a lyophilized powder.



- stable over a wide pH range: 4.0-12.5, optimum pH 7.5-8.0

- not inactivated by metal chelators, by thiol-reactive reagents or by specific trypsin and chymotrypsin inhibitors

- the activity of the enzyme is stimulated by 0.2-1% SDS or by 1-4 M urea

- Ca2+ protects Proteinase K against autolysis, increases the thermal stability and has a regulatory function for the substrate binding site of Proteinase K [6]



- purification of target material from contaminating proteins

- isolation of genomic DNA and mRNA from cultured cells [3]

- removal of DNases and RNases when isolating DNA and RNA from tissues or cell lines [2,3]

- determination of enzyme localization [4]

- improving cloning efficiency of PCR products [5]


Storage Temperature

Lyophilized Proteinase K or solutions in 50 mM Tris-HCl (pH 8.0), 5 mM CaCl2, 50% glycerol (v/v) can be stored at -20°C for at least 12 months from the date of purchase.


Recommended Storage Buffer

- 50 mM Tris-HCl (pH 8.0), 5 mM CaCl2 and 50% (v/v) glycerol (storage at -20ºC)



Phenylmethylsulfonyl fluoride (PMSF) and diisopropyl phosphorofluoridate (DPF) completely inhibit the enzyme. Proteinase K is also inactivated by heating above 65ºC for 20 min.


Quality control

The product passed the quality tests for the presence of endo-, exonucleases and ribonucleases.


Unit definition

One unit of the enzyme liberates Folin-positive amino acids and peptides corresponding to 1 µmol tyrosine in 1 min.



1. Ebeling, W., et al., Proteinase K from Tritirachium album Limber, Eur. J. Biochem., 47, 91-97, 1974.

2. Wiegers, U., Hilz, H., A new method using ‘proteinase K’ to prevent mRNA degradation during isolation from HeLa cells, Biochem. and Biophys. Res. Commun., 44, 513-519, 1971.

3. Hilz, H., et al., Stimulation of proteinase K action by denaturing agents: application to the isolation of nucleic acids and the degradation of “masked” proteins, Eur. J. Biochem., 56, 103-108, 1975.

4. Brdiczka, D., Krebs, W., Localization of enzymes by means of proteases, Biochim. Biophys. Acta, 297, 203-212, 1973.

5. Crowe, J.S., et al., Improved cloning efficiency of polymerase chain reaction (PCR) products after proteinase K digestion, Nucleic Acids Res., 19, 184, 1991.

6. Bajorath, J, et al, The enzymatic activity of proteinase K is controled by calcium., Eur. J. Biochem., 176, 441-447, 1988.


Manufacturer: BLIRT S.A.