2010-06-29
14:00 at HCI J 498

Biopolymer adsorption and dynamics: theoretical approaches at different scales

Roland Netz

Physik Department, TU Munich, Germany

Biopolymer dynamics combines the fields of solvation chemistry, elasticity theory and hydrodynamics. Theoretical approaches span different length scales and rely on simulations, continuum modeling and scaling approaches.

- Many biopolymers readily adsorb on both hydrophobic and hydrophilic surfaces. Single molecule AFM studies yield adsorption energies and point to an extremely high mobility on hydrophobic surfaces.[1] The dominant hydrophobic attraction can be quantitatively explained with classical MD simulations including explicit water. Both water structural effects and dispersion interactions contribute to this solvation attraction. The friction coefficient of bound polymers is very low on hydrophobic substrates, which is traced back to the presence of a vacuum layer between substrate and water, which forms a lubricating cushion on which a polymer can glide. Conversely, friction forces on hydrophilic substrates are large.[2]
- The local dynamics of DNA is scale dependent and exhibits elastic effects, entropic effects and center-of-mass dynamics as one goes from smaller to larger scales, in accordance with recent fluorescence-correlation spectroscopy data.[3]

[1] Peptide adsorption on a hydrophobic surface results from an interplay of solvation, surface and intrapeptide forces, D. Horinek, A. Serr, M. Geisler, T. Pirzer, U. Slotta, S. Q. Lud, J. A. Garrido, T. Scheibel, T. Hugel, R. R. Netz, PNAS 105, 2842 (2008)
[2] Polypeptide friction and adhesion on hydrophobic and hydrophilic surfaces: A molecular dynamics case study, A. Serr, D. Horinek and R.R. Netz, JACS 130, 12408 (2008)
[3] Global cross-over dynamics of single semiflexible polymers, M. Hinczewski, and R.R. Netz, EPL 88 18001 (2009)