Merck, 614850-1SET, Topoisomerase I, His•Tag®, Human, Wild Type, Recombinant, S. frugiperda

General description
Recombinant, human topoisomerase I fused to a His•Tag sequence and expressed in S. frugiperda insect cells. It catalyzes the relaxation of both positive and negative supercoiled DNAs without the requirement of energy. In addition to DNA replication and transcriptional activation, DNA topoisomerase I also plays a role in pre-mRNA splicing, cell cycle and other gene regulatory pathways during cell growth and development. DNA Topo I is an important target for ant-tumor agents as a result of the fact that is causes single-strand DNA breaks of the type that are present in most cancers.
Biochem/physiol Actions
0.1-1 unit (ng) is sufficient for relaxing 0.5 µg of pBR322 supercoiled DNA in a 20 µl reaction.
Packaging
Please refer to vial label for lot-specific concentration.
Physical form
5000 U enzyme in 100 mM KCl, 20 mM Tris-HCl, 1 mM DTT, 200 µM EDTA, 20% glycerol, pH 7.9 and 1 vial dilution buffer (100 mM KCl, 20 mM Tris-HCl, 1 mM DTT, 0.2 mM EDTA, 20% glycerol, pH 8.0).
Preparation Note
Following initial thaw aliquot and freeze (-70°C). For storage of diluted protein, dilute in storage buffer with 500µg/ml molecular biology grade BSA, aliquot, and freeze (-70°C).
Other Notes
Pommier, Y., et al. 1998. Biochim. Biophys. Acta1400, 83.
Pourquier, P., et al. 1997. J. Biol. Chem.272, 26441.
Rossi, F., et al. 1996. Nature381, 80.
Sekiguchi, J., et al. 1996. Proc. Natl. Acad. Sci. USA93, 785.
Giovanella, B.C., et al. 1989. Science246, 1046.
Wang, J,C. 1985. Annu. Rev. Biochem.54, 665.
Legal Information
CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany
HIS TAG is a registered trademark of Merck KGaA, Darmstadt, Germany
Disclaimer
Toxicity: Standard Handling (A)