l General Information |
Product Name | Deoxyribonuclease I from bovine pancreas |
Synonym | DNase I, Deoxyribonucleate 5′-oligonucleotido-hydrolase |
Assay | Standardized vial containing 2,000 Kunitz units of DNase I (D4527), vial of ≥0.25 mg total protein | CAS Number | 9003-98-9 |
Molecular Weight | mol wt ~31 kDa | MDL number | MFCD00130918 |
Suitability | BioReagent |
l Physical and Chemical Information |
Appearance | White to Light Yellow Powder |
Solubility(25°C) | 0.15 M NaCl: soluble 5.0 mg/mL, clear |
l Biological Information |
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+. The pH optimum is found to be between 7 and 8. 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. DNAse I from bovine pancreas consists of four chromatographically distinguishable components, A, B, C, and D, with molar ratios being 4:1:1 respectively. Only minor amounts of D are found. 2-Mercaptoethanol, chelators, sodium dodecyl sulfate (SDS) and actin are known to inhibit the enzyme activity. |
Application | Used for the removal of DNA from protein samples. DNAse I is used to nick DNA as a first step to incorporate labeled bases into DNA. DNAse I from Sigma has been used along with other enzymes for tumor harvest and dissociation, during the isolation and molecular characterization of cancer stem cells in MMTV-Wnt-1 murine breast tumors. Deoxyribonuclease I from bovine pancreas has been used in a study to determine that mammalian deoxyribonucleases I are classified into three types based on differences in their tissue concentrations. Deoxyribonuclease I from bovine pancreas has also been used in a study to compare the three primary structures of deoxyribonuclease isolated from bovine, ovine, and porcine pancreas. |
Preparation Note | The enzyme powder may be reconstituted in water or any buffer at pH 4.0-9.0, except phosphate buffer. Calcium chelators should be avoided. 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. |
Unit Definition | One Kunitz unit will produce a ΔA260of 0.001 per min per mL at pH 5.0 at 25 °C, using DNA, Type I or III as substrate. |
l Storage |
Storage temp. | -20°C |
l Precautions and Disclaimer |
This product is for R&D use only, not for drug, household, or other uses. |
l References |
1. http://www.drugbank.ca 2. https://ncit.nci.nih.gov 3. https://www.ncbi.nlm.nih.gov |
