Ribonuclease A
from bovine pancreas
Catalog Numbers R5125, R4875, R5503, R5000, R5250, and R5500
Storage Temperature –20 °C
沧州日报CAS RN 9001-99-4EC 3.1.27.5 Synonyms: Ribonuclease I; Pancreatic ribonuclease; Ribonuclease 3′-pyrimidinooligonucleotidohydrolase; RNase A; Endoribonuclease I
Product Description
RNase A is an endoribonuclease that attacks at the 3′phosphate of a pyrimidine nucleotide. The sequence of pG-pG-pC-pA-pG will be cleaved to give pG-pG-pCp and A-pG. The highest activity is exhibited with single stranded RNA.1RNase A is a single chain polypeptide containing 4 disulfide bridges. In contrast to RNase B, it
is not a glycoprotein.2
RNase A can be inhibited by alkylation of His 12or His 119, which are present in the
active site of the enzyme.3
Activators of RNase A include potassium and sodium salts.
Molecular mass:4
13.7 kDa (amino acid sequence)Extinction coefficient:5E 1%= 7.1 (280 nm)Isoelectric point:6pI = 9.6
Optimal temperature: 60 °C (activity range of 15–70 °C) Optimal pH:7
7.6 (activity range of 6–10) Inhibitors: ribonuclease inhibitor
Precautions and Disclaimer
This product is for R&D use only, not for drug,
household, or other uses. Please consult the Material Safety Data Sheet for information regarding hazards and safe handling practices.
Note: RNase A is stable to both heat and detergents. In addition, it adsorbs strongly to glass. Scrupulous
precautions are necessary to ensure RNase A residue does not cause artifacts in processes requiring intact RNA.
Preparation Instructions
信道增益When Sigma tests the activity of RNAse A, a stock solution is prepared in water at 1 mg/ml. An RNase A solution can be made free of DNase by boiling. According to a literature method,8prepare a 10 mg/mL stock solution in 10 mM sodium acetate buffer, pH 5.2. Heat to 100 °C for 15 minutes, allow to cool to room temperature, and then adjust to pH 7.4 using 0.1 volume of 1 M
Tris-HCl, pH 7.4. Aliquot and store at –20 °C. If RNase A is boiled at a neutral pH, precipitation will occur. When boiled at the lower pH, some precipitation may occur because of protein impurities that are present.
Storage/Stability
Store at RNase A at –20 °C. Stock solutions stored in frozen aliquots remain active for at least 6 months.RNase A is a very stable enzyme and solutions have been reported to withstand temperatures up to 100 °C. At 100 °C, an RNase A solution is most stable between pH 2.0 and 4.5.9
Procedure
A major application for RNase A is the removal of RNA from preparations of plasmid DNA. For this application, DNase free RNase A is used at a final concentration of
10 µg/ml.
10
References
1.Burrell, M.M., Enzymes of Molecular Biology,
Vol.16, 263-270 (1993).
2.Plummer, T.H., and Hirs, C.H.W., J. Biol. Chem.,
238, 1396-1397 (1963).
3.Heinrikson, R.L. et. al., J. Biol. Chem., 240, 2921-
2934 (1965).
4.Smyth, D.G. et. al., J. Biol. Chem., 238, 227-234
(1963).
5.Keller, P.J. et al., J. Biol. Chem., 233, 344 (1958).闺门旦
6.Tanford, C., and Hauenstein, J. D., J. Am. Chem.
Soc., 78, 5287-5291 (1956).7.Schomberg, D., and Salzmann, M., Enzyme
中小投资
Handbook, Vol. 3, 1-3 under E.C. 3.1.27.5 (1990).
8.Sambrook, J. et. al., Molecular Cloning, A
Laboratory Manual, 2nd ed., 1.51 (1989).
9.Crestfield, A.M. et. al., J. Biol. Chem., 238, 618-621
(1963).
蜜桃片
10.Sambrook, J. et. al., Molecular Cloning, A
Laboratory Manual, 2nd ed., B.17.
RBG,MAM,KTA 09/10-1
Sigma brand products are sold through Sigma-Aldrich, Inc.
Sigma-Aldrich, Inc. warrants that its products conform to the information contained in this and other Sigma-Aldrich publications. Purchaser must determine the suitability of the product(s) for their particular use. Additional terms and conditions may apply.好书
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