The low-temperature dynamic crossover phenomenon in protein hydration water: simulations vs experiments.
A super-Arrhenius-to-Arrhenius dynamic crossover phenomenon has been observed in the translational alpha-relaxation time and in the inverse of the self-diffusion constant both experimentally and by simulations for lysozyme hydration water in the temperature range of TL = 223 +/- 2 K. MD simulations are based on a realistic hydrated powder model, which uses the TIP4P-Ew rigid molecular model for the hydration water. The convergence of neutron scattering, nuclear magnetic resonance and molecular dynamics simulations supports the interpretation that this crossover is a result of the gradual evolution of the structure of hydration water from a high-density liquid to a low-density liquid form upon crossing of the Widom line above the possible liquid-liquid critical point of water.
Lagi
Marco
M
Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Chu
Xiangqiang
X
Kim
Chansoo
C
Mallamace
Francesco
F
Baglioni
Piero
P
Chen
Sow-Hsin
SH
D003080:Cold Temperature; D003198:Computer Simulation; D004798:Enzymes / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009113:Muramidase / Q000737:chemistry; D009502:Neutrons; D011208:Powders; D011506:Proteins / Q000737:chemistry*; D012542:Scattering, Radiation; D014867:Water / Q000737:chemistry*
D004798:Enzymes; D011208:Powders; D011506:Proteins; D014867:Water; D006859:Hydrogen; D009113:Muramidase