| Ribonuclease A is used to isolate DNA for RNA-free DNA. Ribonuclease A hydrolyzes RNA at C and U residues, cleaving between the 3-Phosphate group of a pyrimidine nucleotide and the 5-hydroxyl group of the adjacent nucleotide, i.e., those cleaving cyclic 2,3-pyrimidine nucleotide residues either singly or at the termination of purine nucleotide chains (Volkin and Cohn 1953). The composition and structure of ribonuclease A has been extensively investigated. The tertiary structure was reported by Kartha, et al. (1967) and Lin, (1970). Wang, et al. (1975) indicate that flexibility in a three-dimensional structure is essential for optimal catalytic activity. Ribonuclease is inhibited by heavy metal ions and is competitively inhibited by DNA. The effect of denatured DNA is much greater than that of the native nucleic acid (Sekine et al. 1969). Synonyms: E.C.3.1.27.5, Ribonucleate 3-pyrimidino-oligonucleotidohydrolase, Ribonuclease 1, RNase A, Pancreatic Ribonuclease, Rib 1, Ribonuclease A Family 1, Ribonuclease Pancreatic, Ribonuclease RNase A Family 1, RNAseA, RNase 1, RNASE1, RNS1 CAS No: 9001-99-4 Molecular Weight: 13.7kD Source: Bovine pancreas Appearance: White to off-white powder Activity: 50u/mg protein (Assayed by Kunitz method) Unit Definition: One unit will cause the hydrolysis of RNA at that rate where the velocity constant k equals unity (Kunitz units) at 25C and pH 5.0. DNase (1.5mg/ml): None Detected Protease: None Detected Solubility: Soluble at 100mg/ml in analytical grade water. Colorless, clear, complete. Storage and Stability: Best stored desiccated at -20C or below. Stable for 6 months after receipt. However, the enzyme is stable for years stored as a refrigerated dry powder or frozen in aqueous solution. |
