A physical presentation of the effect of pressure on protein conformat
ional dynamics and Mossbauer spectra was developed. Experimental data
on the influence of pressure on the Mossbauer effect probability, obta
ined by Rayleigh scattering of Mossbauer radiation, were analyzed. Act
ivation volumes of approximately 10-20 angstrom3 were determined for t
he conformational mobility of human serum albumin.