Antibodies under pressure: A Small-Angle X-ray Scattering study of Immunoglobulin G under high hydrostatic pressure

In the present work two subclasses of the human antibody Immunoglobulin G (IgG) have been investigated by Small-Angle X-ray Scattering under high hydrostatic pressures up to 5kbar. It is shown that IgG adopts a symmetric T-shape in solution which differs significantly from available crystal structures. Moreover, high-pressure experiments verify the high stability of the IgG molecule. It is not unfolded by hydrostatic pressures of up to 5kbar but a slight increase of the radius of gyration was observed at elevated pressures. [Display omitted] •IgG solution structure differs considerably from available crystal structures.•It withstands pressures of up to 5kbar for at least several seconds.•A symmetrical T-shape is maintained at up to 4kbar.•Experimental data can be reproduced computationally by a single IgG conformation.