[Conformation stability of immunoglobulin A by the monomolecular layer method]

Human secretory immunoglobulin A (IgA) resistance to surface denaturation as a function of NaCl concentration and pH of aqueous phase has been studied by monomolecular layer method at air-water interface. Ig A has been shown to form monolayers of native molecules oriented horizontally towards interface in pH range from 5.2 to 9.0 and NaCl concentration from 0.15 M to 0.65 M. Beyond these regions surface denaturation rate in directly proportional to H+ and NaCl concentration. It was established that Ig A molecule conformational stability was higher than that of IgG.