Protease K in fungi Pleurodontium albicans is a non-specific protein useful for routine digestion of proteins. Heterosexual serine protease. Proteinase K remains active:

• Over a wide pH range (better activity between 6.5-9.5)
• Under denaturing conditions—for example, in the presence of SDS or urea
• In the presence of metals In the case of chelating agents—such as EDTA
• At relatively high temperatures—the optimal digestion temperature is 65°C

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

Performance and Quality Testing
Endodeoxyribonuclease and exodeoxyribonuclease assay; tests liquid dosage forms for lack of RNase activity.

Unit Definition
One mAnson unit is described as the amount of enzyme that releases 1 µ mole of a Folin-positive amino acid in 1 minute using hemoglobin as a substrate at 37°C.