| Micrococcal nuclease is the extracellular nuclease of S. aureus. It catalyzes preferential endohydrolysis of nucleic acids at adenylate, uridylate, deoxyadenylate or thymidylate-rich sites, yielding 3I nucleotides. CAS No: 9013-53-0 Molecular Weight: 16.8kD Source: S. aureus (Strain Foggi) Appearance: Lyophilized powder Purity: Chromatographically purified. Verified by SDS-PAGE. Protein (%): ~60 Protease: None Detected Optimum pH: 9.2. Note: The enzymic activity has an absolute requirement for Ca2+ and the pH optimum varies according to Ca2+ concentration. Extinction Coefficient: 9.2 Activity: 6000units/mg dry weight. Ca2+ is essential for activity. Both RNase and DNase activities are competitively inhibited by deoxythymidine 3,5 diphosphate. The kinetics of degradation of RNA and DNA differ. However, the enzymic activity has an absolute requirement for Ca2+ and the pH optimum varies according to Ca2+ concentration. Unit Definition: Based upon the release of acid soluble oligonucleotides following nuclease digestion of DNA. One unit corresponds to a change in optical density of 1.0 at 260 nm at 37C and pH 8.0 using DNA as the substrate. Specificity: Exhibits both exo-and endo-5-phosphodiesterase activities against both DNA and RNA. The enzyme catalyzes preferential endohydrolysis of the RNA and DNA at sites rich in adenylate or uridylate and deoxyadenylate or thymidylate. Inhibitors: 5-dioxynucleotides and 5-ribonucleotides are inhibitory with the former demonstrating greatest inhibition. Storage and Stability: Lyophilized powder may be stored at 4C. Stable for 6 months after receipt at -20C. Reconstitute with sterile ddH2O. For long term storage, aliquot and store at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer. |
