title: Protein dynamics and stability: the distribution of atomic fluctuations in thermophilic and mesophilic dihydrofolate reductase derived using elastic incoherent neutron scattering.
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.
authors.affiliation: Heidelberg University, Interdisciplinary Center for Scientific Computing, Computational Molecular Biophysics, Heidelberg, Germany. lars.meinhold@caltech.edu
authors.forename: Lars
authors.initials: L
authors.lastname: Meinhold
authors.forename: David
authors.initials: D
authors.lastname: Clement
authors.forename: Moeava
authors.initials: M
authors.lastname: Tehei
authors.forename: Roy
authors.initials: R
authors.lastname: Daniel
authors.forename: John L
authors.initials: JL
authors.lastname: Finney
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Smith
mesh_terms: D003198:Computer Simulation; D004789:Enzyme Activation; D004795:Enzyme Stability; D008956:Models, Chemical; D008958:Models, Molecular; D033363:Neutron Diffraction / Q000379:methods*; D013696:Temperature; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D013762:Tetrahydrofolate Dehydrogenase