DN25

Deoxyribonuclease I from bovine pancreas

lyophilized powder, Protein ≥85 %, ≥400 Kunitz units/mg protein

• Synonym(s): Deoxyribonuclease, DNase I, Deoxyribonucleate 5′-oligonucleotido-hydrolase
• CAS Number: 9003-98-9
• Enzyme Commission number: 3.1.21.1 (BRENDA, IUBMB)
• EC Number: 232-667-0
• MDL number: MFCD00130918
• UNSPSC Code: 12352204
• NACRES: NA.54

Properties

• biological source: bovine pancreas
• Quality Level: 300
• form: lyophilized powder
• specific activity: ≥400 Kunitz units/mg protein
• mol wt: ~31 kDa
• composition: Protein, ≥85%
• technique(s): DNA extraction: suitable
• solubility: 0.15 M NaCl: soluble 5.0 mg/mL, hazy
• suitability: suitable for molecular biology
• application(s): diagnostic assay manufacturing; diagnostic assay manufacturing
• foreign activity: RNase ≤0.02%
• shipped in: wet ice
• storage temp.: −20°C

Description

General description

DNase I, or Deoxyribonuclease I, is an endonuclease isolated from bovine pancreas.

• Our DNase I Digests double str and single stranded DNA into oligo and mononucleotides.
• Bovine pancreatic DNase exists as four isozymes, having isoelectric points for A, B, C and D: 5.22, 4.96, 5.06 and 4.78.3. The predominant form is A, with smaller amounts of B and C, and only minor amount of D.
• DNase I structure resembles the structure of to exonuclease III. It includes two central ß sheets. Each β sheet is composed of six β-strands. This complex of β sheets is surrounded by extensive loop and α-helical regions. This enzyme shares structural similarity to exonuclease III.^[1]

Application

• Decreases viscosity providing better yields by removing DNA in primary cell isolation:
• Incorporating labelled bases into DNA: DNA nick
• Radioactive labelling
• Bioprocessing applications: DNA removal
• Eliminating genomic DNA from RNA preparations before RT-PCR
• In vitro transcription
• Nick translation
• DNase footprinting
• Actin regulation of actin polymerization in cells, and cell apoptosis
• UV crosslinking of proteins to nucleic acids
• DNase play a role in the regulation of actin polymerization in cells and is involved in apoptosis process ^[1]

Used for the removal of DNA from protein samples.

Biochem/physiol Actions

DNase I is an endonuclease that acts on phosphodiester bonds adjacent to pyrimidines to produce polynucleotides with terminal 5′-phosphates. In the presence of Mg²⁺, DNAse I cleaves each strand of DNA independently and the cleavage sites are random. Both DNA strands are cleaved at approximately the same site in the presence of Mn²⁺.[1] Divalent cations such as Mn²⁺, Ca²⁺, Co²⁺, and Zn²⁺ are activators of the enzyme. A concentration of 5 mM Ca²⁺ stabilizes the enzyme against proteolytic digestion. The pH optimum is found to be between 7 and 8.[2] DNAse I from bovine pancreas consists of four chromatographically distinguishable components, A, B, C, and D, with their molar ratios being 4:1:1 respectively. Only minor amounts of D are found.[3] 2-Mercaptoethanol, chelators, sodium dodecyl sulfate (SDS)[4] and actin[5] are known to inhibit the enzyme activity.

Features and Benefits

Our Deoxyribonuclease DNAse I,is essentially RNAse free product, which support the product application.

Unit Definition

One Kunitz unit will produce a change in A₂₆₀ of 0.001 per min per mL at pH 5.0 at 25 °C, using DNA, Type I or III, as substrate.

Physical form

Crude preparation, contains calcium chloride

Preparation Note

10 mg/mL solution of DNAse I in 0.15 M NaCl may lose <10% of its activity when stored for a week in aliquots at −20 °C. The same solutions stored in aliquots at 2-8 °C can lose approximately 20% activity. It remains active for up to five hours at 60 °C between pH 5 and 7, and loses activity in <10 minutes at 68 °C. It loses activity at the rate of 6%/hour in acetate buffer (pH 5.0) and tris buffer ((pH 7.2) at 1 mg/mL concentration.

Analysis Note

Protein determined by biuret.

Safety Information

• Pictograms: GHS08
• Signal Word: Danger
• Hazard Statements: H334
• Precautionary Statements: P261 - P284 - P501
• Hazard Classifications: Resp. Sens. 1
• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 3
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves