Proteinase K from the fungus Engyodontium album is a non-specific serine protease that is useful for general digestion of proteins.

Proteinase K Remains Active:
• Over a wide pH range (optimal activity between 6.5 and 9.5)
• Under denaturing conditions (e.g. the presence of SDS or urea)
• In the presence of metal chelating agents (e.g. EDTA)
• At comparatively high temperatures (optimum digestion temperature is 65°C)

Applications: Removal of endogenous nucleases during the preparation of DNA and RNA; preparation of tissue sections for in situ hybridization.

Performance and Quality Testing: Endodeoxyribonuclease and exodeoxyribonuclease assays; liquid form tested for absence of RNase activity.

Unit Definition: One mAnson unit is described as that amount of enzyme that liberates 1 μmole of Folin-positive amino acid within one minute at 37°C using hemoglobin as a substrate.