Direct measure of DNA bending by quantum magnetic imaging of a nano-mechanical torque-balance

Zeeshawn Kazi; Isaac M. Shelby; Ruhee Nirodi; Joseph Turnbull; Hideyuki Watanabe; Kohei M. Itoh; Paul A. Wiggins; Kai-Mei C. Fu

arXiv · 2402.17964

Direct measure of DNA bending by quantum magnetic imaging of a nano-mechanical torque-balance

Zeeshawn Kazi·Isaac M. Shelby·Ruhee Nirodi·Joseph Turnbull·Hideyuki Watanabe·Kohei M. Itoh·Paul A. Wiggins·Kai-Mei C. Fu

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Abstract

DNA flexibility is a key determinant of biological function, from nucleosome positioning to transcriptional regulation, motivating a direct measurement of the bend-torque response of individual DNA molecules. In this work, DNA bending is detected using a nano-mechanical torque balance formed by tethering a ferromagnetic nanoparticle probe by an individual DNA molecule to a diamond magnetic field imager. The torque exerted by the DNA in response to bending caused by an applied magnetic torque is measured using wide-field imaging of quantum defects near the surface of the diamond. Qualitative measurements of differences in DNA bio-mechanical binding configuration are demonstrated, and as a proof-of-principle, a quantitative measurement of the bend response is made for individual DNA molecules. This quantum-enabled measurement approach could be applied to characterize the bend response of biophysically relevant short DNA molecules as well as the sequence dependence of DNA bending energy.

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Zeeshawn Kazi, Isaac M. Shelby, Ruhee Nirodi, Joseph Turnbull, Hideyuki Watanabe, Kohei M. Itoh, Paul A. Wiggins, Kai-Mei C. Fu. 2024-02-28. Direct measure of DNA bending by quantum magnetic imaging of a nano-mechanical torque-balance. https://arxiv.org/abs/2402.17964

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