[Conformational stability of immunoglobulin G in monomolecular layers at aqueous NaCl solution-octane interfaces]

Resistance to surface denaturation of human and horse immunoglobulin G (IgG) molecules at aqueous NaCl solution--octane interface as a function of aqueous phase pH and NaCl concentration has been studied by monomolecular layer method. Higher conformational stability of these proteins at oil--water interface as compared to that at air-water interface has been demonstrated. At aqueous solutions of 0.15 M NaCl concentration and pH range from 2.8 to 8.0 units no conformational changes were fixed. With the change of NaCl concentration in aqueous phase from 0.15 to 2.0 M at neutral pH horse IgG molecules did not lose their native conformation. Human IgG molecules were only slightly undergoing denaturation process under the same conditions.