topoisomerase

noun

topo·​isom·​er·​ase ˌtō-pō-ī-ˈsä-mə-ˌrās 

-ˌrāz

: any of a class of enzymes that reduce supercoiling in DNA by breaking and rejoining one or both strands of the DNA molecule

Examples of topoisomerase in a Sentence

Recent Examples on the Web

Each group received different combinations of topoisomerase inhibitors—irinotecan and temozolomide—with or without the monoclonal antibody bevacizumab. —William A. Haseltine, Forbes, 27 Feb. 2025

Many of these carry drugs that inhibit the enzyme topoisomerase 1, which is essential for DNA replication. —Jyoti Madhusoodanan, Scientific American, 1 Mar. 2024

When things start getting too tightly wound, topoisomerase cuts the DNA strand, unwinds it, and reattaches it with a bit more slack. —Cathleen O'Grady, Ars Technica, 15 Nov. 2018

But while gonorrhea has been evolving ways to stop ciprofloxacin from getting in the way of topoisomerase, those strategies don’t work on the new drug. —Cathleen O'Grady, Ars Technica, 15 Nov. 2018

Word History

Etymology

top- + isomerase

First Known Use

1980, in the meaning defined above

Rhymes for topoisomerase

• aminopeptidase
• anticholinesterase
• carboxypeptidase
• hyaluronidase
• ablaze
• airways
• allays
• always
• amaze
• anglaise
• appraise
• archways

Medical Definition

topoisomerase

noun

topo·​isom·​er·​ase ˌtō-pō-ī-ˈsäm-ə-ˌrās, -ˌrāz 

: any of a class of enzymes that reduce supercoiling in DNA by breaking and rejoining one or both strands of the DNA molecule