Deoxyribonuclease I bovine (C15-1355-687)

Application

Deoxyribonuclease I bovine has been used in a study to investigate the inhibition of DNA polymerase by extracts of rat liver. Deoxyribonuclease I bovine has also been used in a study to investigate the effects of ionic strength on enzymic activity.

Deoxyribonuclease I bovine has been used in the preparation of cold cell lysis buffer, complete RNA lysis buffer, cell lysis buffer for testing the expression of recombinant tagged protein.

The enzyme from Sigma has been used for the digestion of DNA extracted from Agave spp. clones. The enzyme was used during a study that investigated the effect of epigenetic changes on the regulatory expression of KNOTTED1-like HOMEOBOX (KNOX) transcription factors.

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. 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. 2-Mercaptoethanol, chelators, sodium dodecyl sulfate (SDS) and actin are known to inhibit the enzyme activity.

Digests single- and double-stranded DNA to a mixture of mono- and oligonucleotides carrying 5′ phosphates and 3′ OH termini. This catalytic activity is divalent ion-dependent. In the presence of Mg²⁺, DNase I hydrolyzes each strand of double-stranded DNA randomly and independently. In the presence of Mn²⁺, both strands can be cleaved.

Features and Benefits

• RNA purification by removing DNA
• Prepare DNA for nick translation¹
• Footprinting assays to determine DNA-protein interactions²

Unit Definition

One unit will produce a ΔA₂₆₀ of 0.001 per min per mL reaction mixture using calf thymus DNA at pH 5.0 and 25°C

Physical form

supplied as a lyophilized powder containing glycine as a stabilizer

Preparation Note

Produced without using any animal cells or animal derived materials.

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 upto five hours at 60 °C 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.