Proteinase K – lyophilised

Description:
Proteinase K is a fungal protease from Tritirachium album. It belongs to the subtilisin family with the classic catalytic triad of Asp³⁹-His⁶⁹-Ser²²⁴ at its active site^[1]. The enzyme is very stable over a wide pH-range, at various salt concentrations and is even active in SDS concentrations up to 0.5%.

Source: Tritirachium album

Usage:
Warm the Proteinase K powder to room temperature before opening.
We recommend to resuspend the enzyme in 50 mM HEPES pH 7.0 to a final concentration of 10-20 mg/ml.
Crystals can be grown using the sitting drop or hanging drop vapor diffusion method.
Following crystallization conditions are suggested for Proteinase K crystal growth^[2,3]:

• • 1.2 M Ammonium Sulfate, 0.1 M Tris-HCl pH 8.0
  • 1.0 M NaNO₃, 100 mM Citrate Buffer pH 6.5

Applications:
Proteinase K can be utilized as model protein in crystallization experiments and X-ray structure analysis.

Selected References:
[1] Larson et al. (2009) High-resolution structure of proteinase K cocrystallized with digalacturonic acid. Acta Cryst. F 65:192.
[2] Müller-Diekmann (2007) On the routine use of soft X-rays in macromolecular crystallography. Part IV. Efficient determination of anomalous substructures in biomacromolecules using longer X-ray wavelengths. Acta Cryst. D 63:366.
[3] Wang et al. (2006) What can be done with a good crystal and an accurate beamline? Acta Cryst. D 62:1475.