Oligomeric Structure of Recombinant Human and Murine Immune Interferons by Means of Sedimentation Equilibrium

Abstract

The oligomeric structure of two recombinant human immune interferon species, one with Cys-Tyr-Cys-Gln ([Cys-Tyr-Cys]rHu-IFN-γ) and the other with Met-Gln-Asp-Pro (rHu-IFN-γ) as the amino-terminal residues, and a recombinant murine immune interferon ([Cys-Tyr-Cys]rMu-IFN-γ) were examined by means of sedimentation equilibrium. All three IFN-γs existed as dimers under nondenaturing conditions. Both [Cys-Tyr-Cys]rHu-IFN-γ and [Cys-Tyr-Cys]rMu-IFN-γ formed higher oligomers, tetramere, and octamers, respectively, under oxidative conditions, whereas rHu-IFN-γ remained as dimers.