Structural correlations and melting of B-DNA fibres

Andrew Wildes (1) , Nikos Theodorakopoulos (2, 3) , Jessica Valle Orero (1, 4) , Santiago Cuesta-Lopez (4) , Jean-Luc Garden (5) , Michel Peyrard (4)

1 ILL - Institut Laue-Langevin
2 Theoretical and Physical Chemistry Institute NHRF
3 Fachbereich Physik [Konstanz]
4 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
5 ThEMA - Thermique Elaboration Matériaux Applications

Despite numerous attempts, the understanding of the thermal denaturation of DNA is still a challenge due to the lack of structural data at the transition since standard experimental approaches to DNA melting are made in solution and do not provide spatial information. We report a measurement using neutron scattering from oriented DNA fibres to determine the size of the regions that stay in the double-helix conformation as the melting temperature is approached from below. A Bragg peak from the B-form of DNA has been observed as a function of temperature and its width and integrated intensity have bean measured. These results, complemented by a differential calorimetry study of the melting of B DNA fibres as well as electrophoresis and optical observation data, are analysed in terms of a one-dimensional mesoscopic model of DNA.

Keywords: neutron scattering; thermal denaturation; DNA

Domains: Physics [physics]; Condensed Matter [cond-mat]; Statistical Mechanics [cond-mat.stat-mech]

Andrew Wildes, Nikos Theodorakopoulos, Jessica Valle Orero, Santiago Cuesta-Lopez, Jean-Luc Garden, et al.. Structural correlations and melting of B-DNA fibres. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2011, 83, pp.061923. ⟨10.1103/PhysRevE.83.061923⟩. ⟨ensl-00600164⟩