Proteinase K, Lyophilized

Proteinase K is a highly active 28,904-Daserine protease isolated from the fungusTritirachium album. The enzyme exhibitsbroad cleavage specificity on native anddenatured proteins and is widely used in thepurification of DNA and RNA. Its activityis increased in the presence of denaturantssuch as SDS (1%) and elevated temperature(50-60°C). The recommended workingconcentration is 50-100 µg/ml for proteinremoval and enzyme inactivation, and up to2 mg/ml for tissue treatment. The Proteinase K,Lyophilized powder can be prepared as a20 mg/ml stock solution in water and storedin aliquots at -20°C. The enzyme is alsoavailable as a ready-to-use concentrated stocksolution (600 mAU/ml) that is convenientfor routine use in most applications. 1 mgof Proteinase K is the equivalent of 30 mAU(AU = Anson unit). The Novagen ProteinaseK products are free of detectable DNase andRNase

Useful for the proteolytic inactivation of nucleases during the isolation of DNA and RNA.
Removes endotoxins that bind to cationic proteins such as lysozyme and ribonuclease A.
Reported useful for the isolation of hepatic, yeast, and mung bean mitochondria
Determination of enzyme localization on membranes
Treatment of paraffin embedded tissue sections to expose antigen binding sites for antibody labeling.
Digestion of proteins from brain tissue samples for prions in Transmissible Spongiform Encephalopathies (TSE) research.

Proteinase K is a stable and highly reactive serine protease. Evidence from crystal and molecular structure studies indicates the enzyme belongs to the subtilisin family with an active-site catalytic triad (Asp³⁹-His⁶⁹-Ser²²⁴). It is stable in a broad range of environments: pH, buffer salts, detergents (SDS), and temperature. In the presence of 0.1-0.5% SDS, proteinase K retains activity and will digest a variety of proteins and nucleases in DNA preparations without compromising the integrity of the isolated DNA.

Toxicity: Harmful (C)

One AU (AU = Anson unit) is defined as the amount of enzyme that liberates 1.0 µmol (181 µg) of tyrosine from casein per minute at pH 7.5 at 37°C.

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