Search Thermo Fisher Scientific
Search Thermo Fisher Scientific
Catalog Number | Quantity |
---|---|
25530031 | 1 g |
25530015 | 100 mg |
Proteinase K from the fungus Engyodontium album is a nonspecific 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., in 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 μmol of Folin-positive amino acid within 1 min at 37°C using hemoglobin as a substrate.
We recommend storing it at 4°C.
Scrape a single colony from the surface of an agar plate and transfer to 12 µL of SCL solution [10 mM Tris-HCl (pH 7.5), 1 mM EDTA, 50 µg/mL proteinase K] and incubate for 15 min at 55 degrees C. Inactivate proteinase K for 15 min at 80 degrees C and add 20 µL of deionized water. Centrifuge at 12,000 x g for 3 min. Transfer the supernatant to a new tube.
Concentration: Generally proteinase K is used in the concentration range of 50 to 500 µg/mL at 65 degrees C in the presence of SDS (0.5-1%).
Temperature optimum: 65 degrees C; 12X more active at 65 degrees C than at 25 degrees C.
pH: Proteinase K is stable over a wide pH range (4.0 to 12.5), with optimal activity at pH 6.5 to 9.5. It is most stable at pH 8.
Inactivation: Heat inactivate Proteinase K at 80 degrees C for 15 min. Phenol extraction is the recommended method to ensure complete inactivation.
Inhibited by: PMSF (0.1 to 1.0 mM of PMSF is usually sufficient for inhibition of Proteinase K)
Not inhibited by: Proteinase K is not inactivated by metal ions, chelating agents (e.g., EDTA), sulfhydryl reagents or by trypsin or chymotrypsin inhibitors. Activity can be stimulated by addition of denaturing agents (SDS and urea).
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