Protein dynamics and stability: The distribution of atomic fluctuations in thermophilic and mesophilic dihydrofolate reductase derived using elastic incoherent neutron scattering

Authors

Lars Meinhold, Heidelberg University
David Clement, University of Waikato
Moeava Tehei, University of WollongongFollow
Roy Daniel, University of Waikato
John L. Finney, University College London
Jeremy C. Smith, University of Tennessee

RIS ID

28403

Publication Details

Meinhold, L., Clement, D., Tehei, M., Daniel, R., Finney, J. L. & Smith, J. C. (2008). Protein dynamics and stability: The distribution of atomic fluctuations in thermophilic and mesophilic dihydrofolate reductase derived using elastic incoherent neutron scattering. Biophysical Journal, 94 (12), 4812-4818.

Abstract

The temperature dependence of the dynamics of mesophilic and thermophilic dihydrofolate reductase is examined using elastic incoherent neutron scattering. It is demonstrated that the distribution of atomic displacement amplitudes can be derived from the elastic scattering data by assuming a (Weibull) functional form that resembles distributions seen in molecular dynamics simulations. The thermophilic enzyme has a significantly broader distribution than its mesophilic counterpart. Furthermore, although the rate of increase with temperature of the atomic mean-square displacements extracted from the dynamic structure factor is found to be comparable for both enzymes, the amplitudes are found to be slightly larger for the thermophilic enzyme. Therefore, these results imply that the thermophilic enzyme is the more flexible of the two.