Evidence for conformational states of poliovirions: effects of cations on reactivity of poliovirions to guanidine.

The kinetics of inactivation of poliovirions were determined in the presence of various concentrations of monovalent and divalent ions, methionine, guanidine and combinations of these at various temperatures. Four states of the virion, under control of the ionic environment, could be recognized which were reversibly interchangeable and yet retained infectious potential. These states were detected by differential sensitivity of the virion to inactivation of infectivity by heat, urea and guanidine. The data are interpreted in terms of conformational structural changes under control of the ionic environment. It is proposed that these various structural conformations are meaningful to the various biologic functional states of the virus.