614850

Topoisomerase I, His•Tag^®, Human, Wild Type, Recombinant, S. frugiperda

• Synonym(s): Topo I, Wild Type
• UNSPSC Code: 12352202
• NACRES: NA.54

Properties

• recombinant: expressed in insect cells (S. frugiperda)
• Quality Level: 100
• Assay: ≥95% (SDS-PAGE)
• form: liquid
• specific activity: 1 units/ng protein
• manufacturer/tradename: Calbiochem^®
• storage condition: OK to freeze; avoid repeated freeze/thaw cycles
• shipped in: wet ice
• storage temp.: −70°C

Description

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 major role in pre-mRNA splicing, cell cycle and other gene regulatory pathways during cell growth and development. Since Topo I can cause large amounts of single-strand DNA breaks it is an important target for antitumor agents. One unit= 1 ng protein.

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.

Warning

Toxicity: Standard Handling (A)

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).

Reconstitution

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

Safety Information

• Storage Class Code: 10 - Combustible liquids
• WGK: WGK 1