The low-temperature inflection observed in neutron scattering measurements of proteins is due to methyl rotation: direct evidence using isotope labeling and molecular dynamics simulations

An inflection seen in atomic mean square displacements measured as a function of temperature on high resolution spectrometers is described by the onset of methyl group rotations. Molecular dynamics simulations have shown that the apparent transition is because of methyl group rotation entering the infinite instrumental resolution of the spectrometer.