Oxidized Derivatives of 5-Methylcytosine Alter the Stability and Dehybridization Dynamics of Duplex DNA
- Paul J. SansteadPaul J. SansteadDepartment of Chemistry, Institute for Biophysical Dynamics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United StatesMore by Paul J. Sanstead
- ,
- Brennan AshwoodBrennan AshwoodDepartment of Chemistry, Institute for Biophysical Dynamics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United StatesMore by Brennan Ashwood
- ,
- Qing DaiQing DaiDepartment of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United StatesMore by Qing Dai
- ,
- Chuan HeChuan HeDepartment of Chemistry, Institute for Biophysical Dynamics, Department of Biochemistry and Molecular Biology and Howard Hughes Medical Institute, The University of Chicago, Chicago, Illinois 60637, United StatesMore by Chuan He
- , and
- Andrei Tokmakoff*Andrei Tokmakoff*E-mail: [email protected]Department of Chemistry, Institute for Biophysical Dynamics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United StatesMore by Andrei Tokmakoff
Abstract

The naturally occurring nucleobase 5-methylcytosine (mC) and its oxidized derivatives 5-hydroxymethylcytosine (hmC), 5-formylcytosine (fC), and 5-carboxylcytosine (caC) play important roles in epigenetic regulation and, along with cytosine (C), represent nucleobases currently implicated in the active cytosine demethylation pathway. Despite considerable interest in these modified bases, their impact on the thermodynamic stability of double-stranded DNA (dsDNA) remains ambiguous and their influence on hybridization kinetics and dynamics is even less well-understood. To address these unknowns, we employ steady-state and time-resolved infrared spectroscopy to measure the influence of cytosine modification on the thermodynamics and kinetics of hybridization by assessing the impact on local base pairing dynamics, shifts in the stability of the duplex state, and changes to the hybridization transition state. Modification with mC leads to more tightly bound base pairing below the melting transition and stabilizes the duplex relative to canonical DNA, but the free energy barrier to dehybridization at physiological temperature is nevertheless reduced slightly. Both hmC and fC lead to an increase in local base pair fluctuations, a reduction in the cooperativity of duplex melting, and a lowering of the dissociation barrier, but these effects are most pronounced when the 5-position is formylated. The caC nucleobase demonstrates little impact on dsDNA under neutral conditions, but we find that this modification can dynamically switch between C-like and fC-like behavior depending on the protonation state of the 5-position carboxyl group. Our results provide a consistent thermodynamic and kinetic framework with which to describe the modulation of the physical properties of double-stranded DNA containing these modified nucleobases.
Cited By
This article is cited by 9 publications.
- Wenting Meng, Hao-Che Peng, Yuanhao Liu, Allison Stelling, Lu Wang. Modeling the Infrared Spectroscopy of Oligonucleotides with 13C Isotope Labels. The Journal of Physical Chemistry B 2023, 127 (11) , 2351-2361. https://doi.org/10.1021/acs.jpcb.2c08915
- Romeo C. A. Dubini, Eva Korytiaková, Thea Schinkel, Pia Heinrichs, Thomas Carell, Petra Rovó. 1H NMR Chemical Exchange Techniques Reveal Local and Global Effects of Oxidized Cytosine Derivatives. ACS Physical Chemistry Au 2022, 2 (3) , 237-246. https://doi.org/10.1021/acsphyschemau.1c00050
- Brennan Ashwood, Nicholas H. C. Lewis, Paul J. Sanstead, Andrei Tokmakoff. Temperature-Jump 2D IR Spectroscopy with Intensity-Modulated CW Optical Heating. The Journal of Physical Chemistry B 2020, 124 (39) , 8665-8677. https://doi.org/10.1021/acs.jpcb.0c07177
- Manjula Jaisal, Rajesh Kumar Reddy Sannapureddi, Arjun Rana, Bharathwaj Sathyamoorthy. 5-Formylcytosine weakens the G–C pair and imparts local conformational fluctuations to DNA duplexes. Physical Chemistry Chemical Physics 2022, 25 (1) , 241-254. https://doi.org/10.1039/D2CP04837J
- Xiao-Cong Zhao, Hai-Long Dong, Xiao-Lu Li, Hong-Yu Yang, Xue-Feng Chen, Liang Dai, Wen-Qiang Wu, Zhi-Jie Tan, Xing-Hua Zhang. 5-Methyl-cytosine stabilizes DNA but hinders DNA hybridization revealed by magnetic tweezers and simulations. Nucleic Acids Research 2022, 50 (21) , 12344-12354. https://doi.org/10.1093/nar/gkac1122
- Kingsley L. Wong, Juewen Liu. Factors and methods to modulate DNA hybridization kinetics. Biotechnology Journal 2021, 16 (11) https://doi.org/10.1002/biot.202000338
- Senta Volkenandt, Frank Beierlein, Petra Imhof. Interaction of Thymine DNA Glycosylase with Oxidised 5-Methyl-cytosines in Their Amino- and Imino-Forms. Molecules 2021, 26 (19) , 5728. https://doi.org/10.3390/molecules26195728
- Jessica Dale, C. Peter Howe, Hedvika Toncrova, Robby Fritzsch, Gregory M. Greetham, Ian P. Clark, Michael Towrie, Anthony W. Parker, Thomas C. McLeish, Neil T. Hunt. Combining steady state and temperature jump IR spectroscopy to investigate the allosteric effects of ligand binding to dsDNA. Physical Chemistry Chemical Physics 2021, 23 (28) , 15352-15363. https://doi.org/10.1039/D1CP02233D
- Romeo C A Dubini, Alexander Schön, Markus Müller, Thomas Carell, Petra Rovó. Impact of 5-formylcytosine on the melting kinetics of DNA by 1H NMR chemical exchange. Nucleic Acids Research 2020, 48 (15) , 8796-8807. https://doi.org/10.1093/nar/gkaa589