Loading...

Vibrational lifetimes of hydrated phospholipids

Jadidi, T ; Sharif University of Technology | 2013

142 Viewed
  1. Type of Document: Article
  2. DOI: 10.1209/0295-5075/102/28008
  3. Publisher: 2013
  4. Abstract:
  5. Large-scale ab initio molecular-dynamics simulations have been carried out to compute, at human-body temperature, the vibrational modes and lifetimes of pure and hydrated dipalmitoylphosphatidylcholine (DPPC) lipids. The projected atomic vibrations calculated from the spectral energy density are used to compute the vibrational modes and the lifetimes. All the normal modes of the pure and hydrated DPPC and their frequencies are identified. The computed lifetimes incorporate the full anharmonicity of the atomic interactions. The vibrational modes of the water molecules close to the head group of DPPC are active (possess large projected spectrum amplitudes) in the frequency range 0.5-55 THz, with a peak at 2.80 THz in the energy spectrum. The computed lifetimes for the high-frequency modes agree well with the recent data measured at room temperature where high-order phonon scattering is not negligible. The computed lifetimes of the low-frequency modes can be tested using the current experimental capabilities. Moreover, the approach may be applied to other lipids and biomolecules, in order to predict their vibrational dispersion relations, and to study the dynamics of vibrational energy transfer
  6. Keywords:
  8. Source: EPL ; Volume 102, Issue 2 , May , 2013 ; 02955075 (ISSN)
  9. URL: http://iopscience.iop.org/article/10.1209/0295-5075/102/28008/meta;jsessionid=22D0F64719538C5CB320A72A4A07ECC2.c1.iopscience.cld.iop.org