The RNase A (10 mg/mL) is an endoribonuclease that specifically degrades single-stranded RNA at C and U residues. Also known as Ribonuclease A, it cleaves the phosphodiester bond between the 5'-ribose of a nucleotide and the phosphate group attached to the 3'-ribose of an adjacent pyrimidine nucleotide. The resulting 2', 3'-cyclic phosphate is hydrolyzed to the corresponding 3'-nucleoside phosphate . Applications --DNase and protease-free --Plasmid and genomic DNA preparation --Removal of RNA from recombinant protein preparations. --Ribonuclease protection assays--Mapping single-base mutations in DNA or RNA SourceBovine pancreas. Molecular Weight13.7 kDa monomer.Definition of Activity UnitOne unit of the enzyme causes an increase in absorbance of 1.0 at 260 nm when yeast RNA is hydrolyzed at 37°C and pH 5.0. Fifty units are approximately equivalent to 1 Kunitz unit. Storage Buffer The enzyme is supplied in: 50 mM Tris-HCl (pH 7.4) and 50% (v/v) glycerol. Quality ControlThe absence of endodeoxyribonucleases, exodeoxyribonucleases and proteases confirmed by appropriate quality tests. Functionally tested for RNA digestion in a plasmid DNA purification procedure.Inhibition and Inactivation·Inhibitors: the most potent inhibitor is a ~50 kDa protein from cytosol of mammalian cells, e.g., RiboLock™ RNase Inhibitor.·Other inhibitors: uridine 2',3'-cyclic vanadate, 5'-diphosphoadenosine 3'-phophate and 5'-diphosphoadenosine 2'-phophate (2), SDS, diethyl pyrocarbonate, 4M guanidinium thyocyanate plus 0.1M 2-mercaptoethanol and heavy metal ions. Inactivated by phenol/chloroform extraction. ·Inactivated by phenol/chloroform extraction.Note·The recommended working concentration for RNase A is 1-100 µg/ml depending on the application. ·The enzyme is active under a wide range of reaction conditions. At low salt concentrations (0 to 100 mM NaCl), RNase A cleaves single-stranded and double-stranded RNA as well the RNA strand in RNA-DNA hybrids. However, at NaCl concentrations of 0.3 M or higher, RNase A specifically cleaves single-stranded RNA.
