Technical Data
Topoisomerase I, DNA (Scl-70)
The topology of the DNA is a crucial issue in different biological processes like recombination, replication, transcription, and chromatin remolding. DNA topoisomerases are enzymes that control the amount of supercoiling in DNA. Without topoisomeras, DNA cannot replicate normally. The protein family of DNA topoisomerases is divided into two types (type I and II) based on their mechanism and physical properties. While the type I topoisomerases are monomeric and do not require ATP, the type II contain multi-subunits and depend on ATP for their activity.The type I enzymes include eukaryotic and bacterial topoisomerase I and III. The type II enzymes include bacterial DNA gyrase and topoisomerase IV and the eukaryotic topoisomerase II. Type I enzymes introduce transient single strand breaks in DNA, while type II enzymes produce transient double strand breaks in the DNA. Human DNA Topoisomerase I belongs to the subtype IB enzymes. The protein has four distinct domains. The N-terminal 214 amino acids are dispensable for relaxation activity and constitutes a hydrophilic and highly protease sensitive region of the protein. There are four nuclear localization signals in the N-terminal domain. The second domain is a core domain of 421 amino acids that is responsible for the single break in the DNA. Recently it was reported that DNA topoisomerase I is involved in modulation of RNA and is present in retroviral particles (like HIV1). Furthermore, the enzyme enhances HIV-1 cDNA production in reverse transcription assays.

Suitable for use in Western Blot. Other applications not tested.

Recommended Dilution:
Western Blot: 1-5ug/ml. Human kidney topoisomerase I is ~ 100kD.
Optimal dilutions to be determined by the researcher.

Storage and Stability:
May be stored at 4C for short-term only. For long-term storage, store at -20C. Aliquots are stable for at least 12 months 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.
MabIgG17C51Affinity Purified
50ug4C (-20C Glycerol)Blue IceHumanMouse
Purified human Topoisomerase I protein.
Purified by immunoaffinity chromatography.
Supplied as a liquid in PBS, pH 7.2, 0.05% sodium azide, before the addition of glycerol to 40%.
Recognizes human topoisomerase I. No reactivity is seen with topoisomerase II alpha or beta proteins.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
1. Takahasi H et al (2000) Hybridoma 19, 331-334; Froelich0Ammon SJ et al (1995) JBC 270, 21429-21432; Champoux JJ et al (2001) 70, 369-413; Takahashi H et al (1995) PNAS 92, 5694-5698