A Mössbauer spectroscopy study of the conformational dynamics of native membrane proteins

Abstract In a Mossbauer study of non-dehydrated membrane proteins from thermophilic green-blue algae we observed the behavior of the “narrow” and “broad” lines of their Mossbauer spectra during the heating from 80 to 270 K and found that the behavior of the full area S F under the spectrum resembles that of the Debye-Waller factor and that quadrupole splitting decreases drastically, from Δ = 0.7 mm/s to Δ ≈ 0, as the temperature is increased from 220 to 270 K. The mathematical treatment of the spectra and decomposition into three components corresponding to thermal, diffusional and conformational motions enabled us to explain the temperature-dependent changes in the spectra.