The Thermally Induced Aggregation of Immunoglobulin G in Solution is Prevented by Amphipols

The thermal stability of immunoglobulin G (IgG) in water was monitored by differential scanning calorimetry, dynamic light scattering, and fluorescence correlation spectroscopy in the presence of an amphiphilic polymer (amphipol). The polymer was shown to decrease significantly the enthalpy of IgG unfolding. IgG did not aggregate upon heating up to 75 °C in the presence of polymer unlike the situation in the absence of polymer. The mixed solutions remained free of aggregates upon cooling.