Investigation of the fluorescence of myosin and its fragments, heavy and light meromyosins, in concentrated solutions of neutral salts.

It is shown that when myosin and heavy (HMM) and light (LMM) meromyosins are treated with concentrated solutions of neutral salts there is change in a number of parameters of the fluorescence spectra of these proteins. For myosin and HMM this change takes place in the region of the same concentrations of LiCl, MgDl2, KSCN where there occurs dissociation of the light chains of the myosin molecule. Change in the fluorescence characteristics of myosin and HMM in the presence of these salts may be caused by two effects: change in the native conformation of the myosin molecule and dissociation of its light chains. The effect of salts on LMM fluorescence is in good agreement with general theory of the influence of concentrated salts on macromolecules.