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Magnetic tweezers measurement of single molecule torque.

ABSTRACT: Torsional stress in linear biopolymers such as DNA and chromatin has important consequences for nanoscale biological processes. We have developed a new method to directly measure torque on single molecules. Using a cylindrical magnet, we manipulate a novel probe consisting of a nanorod with a 0.1 microm ferromagnetic segment coupled to a magnetic bead. We achieve controlled introduction of turns into the molecule and precise measurement of torque and molecule extension as a function of the number of turns at low pulling force. We show torque measurement of single DNA molecules and demonstrate for the first time measurements of single chromatin fibers.

SUBMITTER: Celedon A

PROVIDER: S-EPMC4823137 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature

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Magnetic tweezers measurement of single molecule torque.

Celedon Alfredo A Nodelman Ilana M IM Wildt Bridget B Dewan Rohit R Searson Peter P Wirtz Denis D Bowman Gregory D GD Sun Sean X SX

Nano letters 20090401 4

Torsional stress in linear biopolymers such as DNA and chromatin has important consequences for nanoscale biological processes. We have developed a new method to directly measure torque on single molecules. Using a cylindrical magnet, we manipulate a novel probe consisting of a nanorod with a 0.1 microm ferromagnetic segment coupled to a magnetic bead. We achieve controlled introduction of turns into the molecule and precise measurement of torque and molecule extension as a function of the numbe ...[more]

PMID: 19301859

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