P8107S, Proteinase K, Molecular Biology Grade, 2ml, 800 units/ml, storage: -20°C
Highly characterized for more consistent performance, Proteinase K is a subtilisin-related serine protease that will hydrolyze a variety of peptide bonds. Proteinase K is active in a wide range of temperatures and buffers with optimal activity between 20 and 60°C and a pH between 7.5 and 12.0 (1, 2). Activity is stimulated when up to 2% SDS or up to 4 M urea are included in the reaction (3). Calcium is important for thermostability of Proteinase K but it is not required for catalysis, therefore Proteinase K is also active in buffers containing chelating agents such as EDTA (4).
20 mg/ml, approximately, as determined by UV absorption at 280 nm.
Engyodontium album (Tritirachium album)
- Isolation of plasmid and genomic DNA
- Isolation of RNA
- Inactivation of RNases, DNases and enzymes in reactions
- Removal of enzymes from DNA to improve cloning efficiency (5)
- PCR purification
One unit will digest urea-denatured hemoglobin at 37°C (pH 7.5) per minute to produce equal absorbance as 1.0 μmol of L-tyrosine using Folin & Ciocalteu’s phenol reagent (6).
20 mM Tris-HCl
1 mM CaCl2
pH 7.4 @ 25°C
95°C for 10 min
Calculated: 28.9 kDa
Unit Assay Conditions
0.5–2 μg of Proteinase K is incubated with 2% denatured hemoglobin solution for 10 minutes at 37°C (pH 7.5). After precipitation, neutralization and addition of Folin & Ciocalteu’s phenol reagent, absorbance of soluble cleavage products are measured at 750 nm. Absorbance is compared to a standard curve of L-tyrosine absorbance prepared similarly.