Proteinase K, lyophilized, Specific activity ≥30 U/mg protein, is a broad substrate non-specific serine proteinase. It is very stable at pH 4-12 and can be used in isolating mRNA, genomic DNA and digesting unwanted proteins during DNA and RNA preparations from tissues and cells. It’s also been used on glycoprotein modification and protein structure studies. Proteinase K is active with SDS, urea and EDTA. the very agents that inactivates nucleases.
Proteinase K is used for the isolation of native high molecular genomic nucleic acids. Enzymes like DNases and RNases from microorganisms and mammalian cells are rapidly inactivated by Proteinase K.
Specific Activity: 40 U/mg protein
Source: Tritirachium album limber
Molecular Weight: 29,730
Storage Conditions: Store vial at 2-4ºC upon receipt.
Dissolve and aliquot and store at -20ºC recommended.
Use sterile filtration for liquid enzyme storage if keep it at 2-8ºC over a week.
Storage Buffer: 20 mM Tris-HCl (pH 7.4), 1 mM CaCl2, 50% Glycerol (Dilution buffer without glycerol). QC Assays: Unit Definition: One unit is defined as the amount of enzyme that will liberate 1 μmol of tyrosine per minute at 37ºC, pH7.5.
DNase Activity: None detectable enzyme activity with λ DNA after 6 hrs incubation at 37ºC.
RNase Activity: None detectable ribonuclease activity after 16 hrs incubation at 25ºC.
Adding Proteinase K already during the cell lysis enables the isolation of highly native undamaged high molecular DNA or RNA. A variety of methods have been established, which are documented in numerous publications.
Recently, Proteinase K has been used for the detection of BSE forming proteins which are uniquely resistant towards the enzyme's proteolytic cleavage.
Proteinase K is very useful in the analysis of membrane structure by means of modification of proteins and glycoproteins on cell surfaces.
Because of the cleavage specificity Proteinase K, characteristic fragments of proteins are obtained which are helpful in revealing the structure and function of proteins, particularly enzymes.