Hj. Steinhoff et al., PROTEIN DYNAMICS AND EPR-SPECTROSCOPY - COMPARISON OF MOLECULAR DYNAMIC SIMULATIONS WITH EXPERIMENTS, Berichte der Bunsengesellschaft fur Physikalische Chemie, 97(2), 1993, pp. 163-171
Citations number
34
Journal title
Berichte der Bunsengesellschaft fur Physikalische Chemie
Electron paramagnetic resonance (EPR) experiments and molecular dynami
cs simulations on the residual motion of hemoglobin bound spin labels
provide information about dynamical and rate processes in proteins. Ra
pid (ps time range) reorientational fluctuations of the nitroxide ring
of the spin labels within a conformational substate can be experiment
ally characterized and distinguished from low frequency (ns time range
) transitions between the conformational substates which are observed
above 200K in solved samples. A comparison of the experimentally deter
mined magnitudes and frequencies of the reorientational motions and th
e results of molecular dynamics simulations for several nitroxide loca
lizations yields good agreement for the short time dynamics. Evidence
for relatively large scale motions involving rare jumps are observed i
n the molecular dynamics trajectories. A simple approach using Kramers
' theory and a two state jump model permits to combine EPR results and
molecular dynamics simulations in the case of these rare events.