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Product details

Size: 1 ml                  Store at -20℃



  • Ready-to-use solution
  • Active in a wide range of reaction products



Proteinase K is an endolytic protease that cleaves peptide bonds at the carboxylic sides of aliphatic, aromatic or hydrophobic amino acids.

The Proteinase K is classified as a serine protease. The smallest peptide to be hydrolyzed by this enzyme is a tetrapeptide.



  • Isolation of genomic DNA from cultured cells and tissues
  • Removal of DNases and RNases when isolating DNA and RNA from tissues or cell lines
  • Determination of enzyme localization
  • Improving cloning efficiency of PCR products


Quality Control:

The absence of endo-, exodeoxyribonucleases and ribonucleases confirmed by appropriate quality tests.


Concentration:  20 mg/ml



Pichia pastoris cells with a cloned gene encoding Tritirachium album endolytic protease (Proteinase K).

Molecular Weight: 28.9 kDa monomer (6).


Definition of Activity Unit:

One unit of the enzyme liberates Folin-positive amino acids and peptides corresponding to 1 µmol tyrosine in 1 min at 37°C using denatured hemoglobin as substrate.Enzyme activity is assayed in the following mixture: 0.08 M potassium phosphate (pH 7.5), 5 M urea, 4 mM NaCl, 3 mM CaCl2 and 16.7 mg/ml hemoglobin.


Storage Buffer

The enzyme is supplied in: 50 mM Tris-HCl (pH 7.5), containing 5 mM calcium chloride and 50% (v/v) glycerol.


Inhibition and Inactivation

Inhibitors: Proteinase K is not inactivated by metal chelators, by thiol-reactive reagents or by specific trypsin and chymotrypsiinhibitors. Phenylmethylsulfonyl fluoride and diisopropyl phosphorofluoridate completely inhibit the enzyme.

Inactivated by heating at 95°C for 10 minutes.



Optimum activity at 50-55°C.

Rapid denaturation of enzyme occurs at temperatures above 65°C.

The recommended working concentration for Proteinase K is 0.05-1 mg/ml. 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.

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

Proteinase K (Solution)

  • Ships in: 5 Business Days



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