title: Association-dissociation behavior of sesame alpha-globulin in electrolyte solutions.
abstract: The major protein fraction, alpha-globulin, of sesame seed (Sesamum indicum L.) contains subunits which are associated predominantly by hydrophobic interactions. Effects of various salts show the following effectiveness of anions in dissociating the proteins, SO4(2-) less than Cl- less than Br- less than ClO4- less than SCN- less than or equal to I- less than CCl3COO-, the first two members being association-inducing ions. CCl3COONa is found to be the most effective among the series in causing dissociation. The cations Li+, Na+, K+, and Cs+ induce association, the order of effectiveness being Cs+ approximately K+ greater than or equal to Na+ greater than Li+. The low concentration of salts (anions) necessary to induce dissociation does not involve a detectable change in protein conformation. The discrepancy between the effectiveness of the anions in dissociating the protein and the Hofmeister pattern of these ions has been discussed.
mesh_terms: D005916:Globulins; D046911:Macromolecular Substances; D008970:Molecular Weight; D009994:Osmolar Concentration; D011485:Protein Binding; D012639:Seeds / Q000032:analysis*; D013696:Temperature; D014461:Ultracentrifugation
chemical_list: D005916:Globulins; D046911:Macromolecular Substances