Proteinase K

Proteinase K is a serine protease from the family of subtilisin- like protease. It requires the presence of calcium to be active (in an environment without Ca 2+ its activity decreases by about 80%). The optimum pH is 8, however, the enzyme remains active over a wide range of pH values. The reaction rate increases significantly with temperature (the enzyme is stable up to about 60 °C) and with the addition of SDS.

Proteinase K is used to degrade proteins in cell lysates and to purify nucleic acids. It inactivates DNases and RNases very effectively.