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 nickRadioactive labellingBioprocessing applications: DNA removalEliminating genomic DNA from RNA preparations before RT-PCRIn vitro transcriptionNick translationDNase footprintingActin regulation of actin polymerization in cells, and cell apoptosisUV crosslinking of proteins to nucleic acidsDNase play a role in the regulation of actin polymerization in cells and is involved in apoptosis process [1]
• 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.