P6556

Proteinase K from Tritirachium album

lyophilized powder, ≥30 units/mg protein

• Synonym(s): Endopeptidase K
• CAS Number: 39450-01-6
• Enzyme Commission number: 3.4.21.64 (BRENDA, IUBMB)
• EC Number: 254-457-8
• MDL number: MFCD00132129
• eCl@ss: 32160410
• NACRES: NA.54

Properties

• form: lyophilized powder
• Quality Level: 300
• specific activity: ≥30 units/mg protein
• mol wt: 28.93 kDa
• solubility: H₂O: soluble 1 mg/mL, clear, colorless
• foreign activity: Dnase ≤30 Kunitz units/mg solid; RNase ≤0.003 Kunitz units/mg solid
• shipped in: wet ice
• storage temp.: −20°C

Description

Application

Product P6556 is provided as a lyophilized powder. Product P6556 has been used to break down human lens protein. Protease footprinting by Proteinase K digestion can reveal protein-protein surface interactions. The enzyme from Sigma has been used in the pre-hybridization step of chicken embryos. It has also been used for the enrichment of PrP^Sc, a prion protein that is present in sheep, hamster and mouse scrapie samples.

Proteinase K is useful for the proteolytic inactivation of nucleases during the isolation of DNA and RNA.
It is used for the removal of endotoxins bound to cationic proteins such as lysozyme and ribonuclease A.
It is useful for the isolation of hepatic, yeast, and mung bean mitochondria
and is used to determine enzyme localization on membranes
It is used for the treatment of paraffin embedded tissue sections to expose antigen binding sites for antibody labeling and
for digestion of proteins from brain tissue samples for prions in Transmissible Spongiform Encephalopathies (TSE) research. Product P6556 is provided as a lyophilized powder. Product P6556 has been used to break down human lens protein.

Useful for the proteolytic inactivation of nucleases during the isolation of DNA and RNA.
Removes endotoxins that bind to cationic proteins such as lysozyme and ribonuclease A.
Reported useful for the isolation of hepatic, yeast, and mung bean mitochondria
Determination of enzyme localization on membranes
Treatment of paraffin embedded tissue sections to expose antigen binding sites for antibody labeling.
Digestion of proteins from brain tissue samples for prions in Transmissible Spongiform Encephalopathies (TSE) research.

Biochem/physiol Actions

Proteinase K has a broad specificity and degrades many proteins even in the native state. It mainly cleaves the peptide bond adjacent to the carboxyl group of aliphatic and aromatic amino acids with blocked α-amino groups. The optimum pH is between 7.5-9.0 and the isoelectric point is 8.9 Ca²⁺ (1-5 mM) is required for activation. Proteinase K is inhibited by diisopropyl fluorophosphate (DFIP), and phenylmethanesulfonyl fluoride (PMSF).

Proteinase K is a stable and highly reactive serine protease. Evidence from crystal and molecular structure studies indicates the enzyme belongs to the subtilisin family with an active-site catalytic triad (Asp³⁹-His⁶⁹-Ser²²⁴). It is stable in a broad range of environments: pH, buffer salts, detergents (SDS), and temperature. In the presence of 0.1-0.5% SDS, proteinase K retains activity and will digest a variety of proteins and nucleases in DNA preparations without compromising the integrity of the isolated DNA.

Unit Definition

One unit will hydrolyze urea-denatured hemoglobin to produce color equivalent to 1.0 μmole of tyrosine per min at pH 7.5 at 37 °C (color by Folin-Ciocalteu reagent).

Safety Information

• Pictograms: GHS08
• Signal Word: Danger
• Hazard Statements: H315 - H319 - H334
• Precautionary Statements: P261 - P264 - P280 - P284 - P302 + P352 - P305 + P351 + P338
• Hazard Classifications: Eye Irrit. 2 - Resp. Sens. 1 - Skin Irrit. 2
• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 1
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves