Effect of denaturants on the emulsifying activity of proteins

Abstract

The relationship between protein flexibility and emulsifying activity was investigated by disrupting disulfide bonds and/or noncovalent interactions of the protein. Oil-in-water emulsions using model proteins (apomyoglobin, beta-casein, alpha-casein, lysozyme, bovine serum albumin, kappa-casein, and beta-lactoglobulin) were made in the presence of chemical denaturants (dithiothreitol and/or urea). In most cases, the presence of denaturants enhanced emulsifying activity. The effect was protein-specific and depended on the relative importance of disulfide bonds and noncovalent interactions in stabilizing the native conformation of each protein. Implications for the design of novel protein emul..