topoisomerases

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Related to Topoisomerase: DNA gyrase

topoisomerases

[¦tä·pō·ī′säm·ə‚rās·əz]
(biochemistry)
Any of a group of enzymes capable of relaxing, unwinding, unpackaging, or changing the degree of supercoiling of deoxyribonucleic acid fiber.
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A new class of cancer drugs -- topoisomerase inhibitors -- is now in use in the United States for treating certain cancers.
The researchers looked at how cancer cells reacted when given PARP inhibitors alongside a type of chemotherapy called topoisomerase I poisons.
A new high-throughput assay, developed recently in the laboratory of Prof Tony Maxwell of the John Innes Centre (and co-founder of Inspiralis), will also provide a huge advance on the standard gel-based screening method for topoisomerase inhibitors.
Fluorescence spectroscopy studies of vaccinia type IB DNA topoisomerase. Closing of the enzyme clamp is faster than DNA cleavage.
"The finding that PARP inhibitors improve the anti-cancer activity of Topoisomerase 1 poisons indicates they may be useful in the treatment of bowel cancer.
Topoisomerase II(alpha) amplification and anthracycline-based chemotherapy: the jury is still out.
Specific examples are topoisomerases that belong to the nuclear DNA replication and RNA transcription machinery, where they are key components in DNA-RNA synthesis.
HER-2 amplification and topoisomerase IIalpha gene aberrations as predictive markers in node-positive breast cancer patients randomly treated either with an anthracycline-based therapy or with cyclophosphamide, methotrexate, and 5-fluorouracil.
Glaxo's new compound latches onto topoisomerase, which helps bacteria produce proteins and replicate.
PASS prediction of topoisomerase I inhibitor activity Molecules Pass activity Pass inactivity (Topoisomerase I (Topoisomerase I inhibitory) inhibitory) A Camptothecin 0.952 0.001 B Irinotecan 0.781 0.002 C Topotecan 0.846 0.002 D 10-Hydroxycamptothecin 0.948 0.001 E 9-Nitrocamptothecin 0.858 0.002 Table 3.
Topoisomerase II: Studies have found that tumors with higher levels of topoisomerase II (topo-II) were more responsive to anthracyclines, but the reverse was also true, where tumors with topo-II deletion also had a high response.
Substitution of conserved residues within the active site alters the cleavage religation equilibrium of DNA topoisomerase I.