Emulsification of aqueous protein solutions in methylene chloride triggered the formation of water-insoluble aggregates at a water/methylene chloride interface. As a result, the amounts of β-lactoglobulin and ovalbumin recovered in water were 36 and 44%, respectively. Addition of 5 mm CHAPS in the aqueous phase raised the degree of β-lactoglobulin recovery to 96%. Sodium taurocholate, however, failed to improve protein recovery. The stabilizing effect of CHAPS was also protein-specific and concentration-dependent: at ≥5 mm, the surfactant caused unfolding of ovalbumin to make a water-soluble oligomer. CHAPS thus stabilizes proteins at an interface.
- Protein stability