Oil/Alkanethiol Layers for the Study of Emulsified Protein Conformation by Surface Plasmon Resonance Using Monoclonal Antibodies

Abstract

A method combining surface plasmon resonance and epitope mapping was developed to study the protein conformation at the oil/water interface of an emulsion. The conformation of β-lactoglobulin stabilizing dodecane/water and miglyol/water interfaces was investigated using five anti-β-lactoglobulin monoclonal antibodies. The developed method allows us to specifically recognize the emulsified β-lactoglobulin at the surface of a sensor chip with good repeatability; i.e., standard deviations range between 0.7 and 3.6%. Considering that the monoclonal antibodies, recognizing conformational epitopes, still bind to β-lactoglobulin at oil/water interfaces, it is concluded that the protein retains a globular conformation. It is shown that the inhibition-binding values of two pairs of Mabs are different for β-lactoglobulin stabilizing dodecane/water and miglyol/water interfaces. This indicates that the conformations of emulsified β-lactoglobulin are slightly different according to the nature of the oil phase.