产品名称

Deoxyribonuclease I from bovine pancreas

一般描述

Deoxyribonuclease I (DNase I) is an endonuclease isolated from bovine pancreas that digests double 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.

别 称

DNase I, Deoxyribonucleate 5′-oligonucleotido-hydrolase

含 量

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

CAS  NO.

9003-98-9

分子量

mol wt ~31 kDa

MDL  number

MFCD00130918

适用范围

生物试剂

l  理化信息

外 观

白色至浅黄色至浅棕色冻干粉末

物理形态

Crude preparation, contains calcium chloride

溶解性(25°C)

0.15M NaCl: soluble 5.0 mg/mL, hazy

l  生物学信息

生物活性/药理作用

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

应 用

Used for the removal of DNA from protein samples.

DNAse I is used to nick DNA as a first step to incorporate labeled s into DNA. The enzyme from Sigma has been used during the isolation of plasma membrane vesicles from Neurospora crassa cell culture. It has also been used along with trypsin for the preparation of single cell suspension from rat testes.

Deoxyribonuclease I from bovine pancreas has been used in a study to compare several procedures for reducing RNase contamination in preparations of DNase. Deoxyribonuclease I from bovine pancreas has also been used in a study to investigate the effect of the composition of sodium dodecyl sulfate preparations on the renaturation of enzymes after polyacrylamide gel electrophoresis.

样品准备说明

10mg/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 pH5 and 7, and loses activity in <10 minutes at 68°C. It loses activity at  the rate of 6%/hour in acetate buffer (pH5.0) and tris buffer ((pH7.2) at 1mg/mL concentration.

有效单位定义

One Kunitz unit will produce a change in A²⁶⁰ of 0.001 per min per mL at pH5.0 at 25°C, using DNA, Type I or III, as substrate.

l  存储

存储温度

-20°C

l  注意事项及免责声明

本产品仅用于实验研究，不得作为药物使用，不得用于家用或其它用途。

l  参考文献

1.    http://www.drugbank.ca

2.    https://ncit.nci.nih.gov

3.  https://www.ncbi.nlm.nih.gov