Merck, 10109142001, RNase A

General description
Bovine pancreatic RNase A is a member of the RNase A protein superfamily. It is one of the most characterized proteins, and is a kidney shaped basic protein. This protein is composed of 124 amino acids. In its native form, RNase A exists as a homodimer.
Application
For analytical purposes
Isolation of DNA (for this purpose, RNase A should be boiled)
For cell cycle analysis by flow cytometry and propidium iodide (PI) staining

Biochem/physiol Actions
RNase A catalyzes the transphosphorylation and degradation of RNA. It was the first protein identified to exhibit DNA melting functionality. This enzyme binds to several binding sites on single stranded (ss) RNA polynucleotide chain before degrading it. It interacts with ssDNA in a similar manner, which is responsible for its ‘DNA unwinding′ property. RNase A dimer obtained through tandemization shows toxicity to cancer cells.
Preparation Note
RNase A can be dissolved at a concentration of 1 to 10 mg/ml in 10 mM Tris-HCl, pH 7.5, 15 mM NaCl, heated to 100 °C for 15 minutes to inactivate contaminating DNases and cooled slowly to room temperature and dispend into aliquots. Roche recommends subsequent storage at -15 to -25 °C.
Other Notes
For life science research only. Not for use in diagnostic procedures.
One unit is the enzyme activity that causes a decrease in absorbance of A₀ to A₁ within 1 minute under assay conditions. A₀ to A₁ corresponds to the total conversion, A₁ being the final absorbance.