[Identical nature of the differences between normal and myeloma IgG in the mouse and man determined by the monolayer method].

The surface denaturation kinetics of mouse normal IgG and IgGl kappa secreted by myeloma MOPC-21 was studied in monomolecular layers at the air-water interface. Based on the denaturation kinetics data the orientation of the native IgG molecules was determined relative to the interface surface, which turned out to be horizontal for normal IgG and vertical for myelomic ones. As regards the orientation in the monolayers and the rate of surface denaturation, the mouse normal IgG were found to be similar to normal IgG from other species. Like human myelomic IgG, MOPC-21 IgGl kappa differed from normal IgG in both the orientation and lesser native structure stability.