In vitro assembly of poliovirus 14 S subunits: disoxaril stabilization as a model for the antigenicity conferring activity of infected cell extracts.

14 S subunits of poliovirus at 37 degrees undergo a rapid thermodenaturation, whereby all neutralizing epitopes are lost. This denaturation is prevented by 1 microgram/ml disoxaril, up to 42 degrees. In the absence of disoxaril, self-assembly of 14 S subunits at 37 degrees yields H-antigenic empty capsids. However, in the presence of disoxaril, and provided the molar ratio of disoxaril per 14 S subunit exceeds 7, the empty capsids generated by self-assembly are N-antigenic, and indistinguishable from native procapsids extracted from infected cells.