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T9069

Sigma-Aldrich

Topoisomerase I human

buffered aqueous glycerol solution, ≥2 units/μL

Synonym(s):

DNA Topoisomerase I

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About This Item

Enzyme Commission number:
MDL number:
UNSPSC Code:
12352204
NACRES:
NA.54

recombinant

expressed in baculovirus

Quality Level

form

buffered aqueous glycerol solution

mol wt

100 kDa

concentration

≥2 units/μL

UniProt accession no.

storage temp.

−70°C

Gene Information

human ... TOP1(7150)

General description

Topoisomerase I (TOP1) is mapped to human chromosome 20q12. TOP1 is a 91 kDa type IB enzyme and consists of N-terminal highly charged domain, a core, linker domain and a C-terminal catalytic domain with Tyr-723 active site residue.

Application

Topoisomerase I has been used in a study to assess implications for the regulation of HIV-1 replication. Topoisomerase I has also been used in a study to investigate the tumor suppressor protein kinase Chk2 is a mediator of anoikis of intestinal epithelial cells.
Topoisomerase I human has been used for Topoisomerase I assay for screening inhibitors.

Biochem/physiol Actions

Topoisomerase I human (TOP1) interacts with DNA by wrapping and takes a bi-lobed conformation. TOPI is essential for normal development and transcriptional regulation. Variants in the TOP1 gene is observed in patients with colorectal cancer.
Topoisomerase I relaxes supercoiled DNA molecules. The enzyme initiates transient breakages and rejoins of phosphodiester bonds in superhelical turns of closed-circular DNA. Enzyme activity is independent of right- and left-handed superhelices.

Unit Definition

One unit will relax 0.25 μg of supercoiled plasmid DNA in 30 minutes at pH 7.9 at 37 °C.

Physical form

Solution containing 20 mM sodium phosphate, pH 7.4, 300 mM NaCl, 50 μg/mL BSA, 50% glycerol, and between 25-100 mM imidazole (concentration will be lot dependent).

Pictograms

Health hazard

Signal Word

Danger

Hazard Statements

Precautionary Statements

Hazard Classifications

Repr. 1B

Storage Class Code

6.1C - Combustible acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects

WGK

WGK 1

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable


Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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Topoisomerase I in human disease pathogenesis and treatments
Li M and Liu Y
Genomics, Proteomics & Bioinformatics, 14(3), 166-171 (2016)
Mechanisms of topoisomerase I (TOP1) gene copy number increase in a stage III colorectal cancer patient cohort
Smith DH, et al.
Testing, 8(4), e60613-e60613 (2013)
Molecular Networking Reveals Two Distinct Chemotypes in Pyrroloiminoquinone-Producing Tsitsikamma favus Sponges
Kalinski JCJ, et al.
Marine drugs, 17(1), 60-60 (2019)
Binding and dissociation of human topoisomerase I with hairpin-loop RNAs: implications for the regulation of HIV-1 replication
Takahashi H, Sawa H, Hasegawa H,
Biochemical and Biophysical Research Communications, 297(3), 593-599 (2012)
Novel insights into catalytic mechanism from a crystal structure of human topoisomerase I in complex with DNA
Redinbo MR, et al.
Biochemistry, 39(23), 6832-6840 (2000)

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