Enzyme Dynamics and Activity: Time-Scale Dependence of Dynamical Transitions in Glutamate Dehydrogenase Solution
Daniel, R. M., Finney, J. L., Reat, V., Dunn, R., Ferrand, M. & Smith, J. C. (1999). Enzyme Dynamics and Activity: Time-Scale Dependence of Dynamical Transitions in Glutamate Dehydrogenase Solution . Biophysical journal, 77, 2184- 2190.
Permanent Research Commons link: https://hdl.handle.net/10289/1287
We have examined the temperature dependence of motions in a cryosolution of the enzyme glutamate dehydrogenase (GDH) and compared these with activity. Dynamic neutron scattering was performed with two instruments of different energy resolution, permitting the separate determination of the average dynamical mean square displacements on the sub-~100 ps and sub-~5 ns time scales. The results demonstrate a marked dependence on the time scale of the temperature profile of the mean square displacement. The lowest temperature at which anharmonic motion is observed is heavily dependent on the time window of the instrument used to observe the dynamics. Several dynamical transitions (inflexions of the mean squared displacement) are observed in the slower dynamics. Comparison with the temperature profile of the activity of the enzyme in the same solvent reveals dynamical transitions that have no effect on GDH function.
This article has been published in the journal: Biophysical journal. Copyright © 1999 by the Biophysical Society.