Probing the structure of long DNA molecules in solution using synchrotron radiation linear dichroism

Martyn Rittman, Søren Vrønning Hoffmann, Emma Gilroy, Matthew R. Hicks, Bärbel Finkenstadt, Alison Rodger

Research output: Contribution to journalArticleResearchpeer-review

7 Citations (Scopus)

Abstract

Linear dichroism (LD), a spectroscopic method for aligned samples, has been used with a synchrotron radiation source to reveal insights into the structure and stability of DNA with increasing salt concentrations (thus stabilizing the base pairing) and increasing temperature while remaining below the melting point (thus destabilizing the base pairing). Measurements have been made from 350 nm to 182 nm, and the spectral changes observed quantified using a Bayesian Markov chain Monte Carlo (MCMC) algorithm, which uses statistical methods to fit to experimental data. Based on literature H-D exchange experiments, we surmise that the cause of the spectral variations is the induction of transient single stranding of tracts in the DNA polymer, particularly those with significant content of the weaker AT base pairs. More detailed analysis of the LD data will require better nucleotide transition polarization assignments.

Original languageEnglish
Pages (from-to)353-366
Number of pages14
JournalPhysical Chemistry Chemical Physics
Volume14
Issue number1
DOIs
Publication statusPublished - 7 Jan 2012
Externally publishedYes

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