EFFECT OF DISSOCIATION AND CONFORMATIONAL-CHANGES ON THE SURFACE BEHAVIOR OF PEA LEGUMIN

In order to improve knowledge of the influence of dissociation of pea legumin on the surface behavior, the influence of pH and the effect of succinylation on the kinetics of adsorption have been studied at the air/water interface. Ultracentrifugation and the Wilhemy plate method were used, respectively, for the characterization of the protein and the interfacial tension measurements. Dissociation results in an improvement in the ability of the protein to diffuse to the interface whereas the charge of the molecule influences the kinetic parameters of anchorage and conformational rearrangement in the occupied interfacial layer. These effects are discussed in relation first to the dissociation of the oligomeric 12S globulin into subunits, then to the unfolding of these subunits, and finally to the charge variations and location along the primary sequence of legumin. © 1992.