Renaturation of Inactivated Interferons by “Defensive Reversible Denaturation”

Abstract Interferon preparations whose activities had been either partially or completely destroyed by a variety of denaturing conditions could be restored to full activity by converting the inactive conformations to linear random coils and “defending” these linear polypeptides with the anionic detergent, sodium dodecyl sulfate, prior to renaturation. Complete restoration of biological activity of both mouse interferons and human fibroblast interferon required that disulfide bonds be reduced prior to renaturation, but partial reactivation was possible without reduction; these data suggest that both mouse and human fibroblast interferon preparations contain distinct molecular species of interferons.