Direct Determination of the Base-Pair Force Constant of DNA from the Acoustic Phonon Dispersion of the Double Helix

作者：van Eijck L^*; Merzel F; Rols S; Ollivier J; Forsyth V T; Johnson M R

来源：Physical Review Letters, 2011, 107(8): 088102.

DOI：10.1103/PhysRevLett.107.088102

Quantifying the molecular elasticity of DNA is fundamental to our understanding of its biological functions. Recently different groups, through experiments on tailored DNA samples and numerical models, have reported a range of stretching force constants (0.3 to 3 N/m). However, the most direct, microscopic measurement of DNA stiffness is obtained from the dispersion of its vibrations. A new neutron scattering spectrometer and aligned, wet spun samples have enabled such measurements, which provide the first data of collective excitations of DNA and yield a force constant of 83 N/m. Structural and dynamic order persists unchanged to within 15 K of the melting point of the sample, precluding the formation of bubbles. These findings are supported by large scale phonon and molecular dynamics calculations, which reconcile hard and soft force constants.

• 出版日期2011-8-19