[A study of the dynamic properties of membrane proteins using Mössbauer spectroscopy]

While studying the parameters of "narrow" and "broad" lines appearing in Mössbauer spectra of undehydrated membrane proteins heated from 80 to 280 K it has been for the first time found for proteins that the behavior of the complete area of spectrum S does not differ from that of Debye-Waller factor. An abrupt decrease of quadrupole splitting value from delta = 0.7 mm/s to delta = 0 within the temperature range 220-270 K. Computation of the spectra with their division into 3 components responding respectively by heat, diffusion and conformational movement made possible explanation of all the evolutionary changes proceeding in them with the temperature rise. Preservation of the complete area of the spectrum S (T) is conditioned by the increase of the component responsive to conformational changes of Fe atom within 230-270 K. These movements "suppress" quadrupole splitting observed in the spectra at low temperatures. Dynamic mobility is considered in terms of the Fe atom movement in the biphase potential.