Thermo Fisher, 38042024, Topoisomerase I

Thermo Fisher, 38042024, Topoisomerase I Topoisomerase I (DNA-relaxing enzyme) catalyzes the removal of superhelical turns from covalently closed DNA by a transient breakage and rejoining of phosphodiester bonds. Topoisomerase I is active in the presence of EDTA.
Applications:Relaxing positively and negatively supercoiled DNA (1). Producing DNA topoisomers (2).
Source:Purified from calf thymus.
Performance and Quality Testing:Endodeoxyribonuclease, 3´ and 5´ exodeoxyribonuclease, and phosphatase assays; conversion of super-coiled DNA to relaxed DNA.
Unit Definition:One unit catalyzes the conversion of 0.
5 μg of superhelical Φ X174 RF DNA to a relaxed state in 30 min. at 37°C.
Unit Reaction Conditions:50 mM Tris-HCl (pH 7.
5), 50 mM KCl, 10 mM MgCl2, 0.
1 mM EDTA, 0.
5 mM DTT, 30 μg/ml/BSA, 0.
5 μgΦ X174 RF DNA, and enzyme in 50 μl for 30 min. at 37°C.
Product Type: Topoisomerase I
Quantity: 500 U
Shipping Condition: Wet Ice
Enzyme: Topoisomerase
Unit Size: Each