Electrophoretic migration of adenovirus hexon under non-denaturing conditions.

While SDS-PAGE/immunoblotting is a valuable approach for the characterization of monoclonal antibodies, the denaturing conditions involved can compromise the recognition of conformational epitopes. This report demonstrates that a group specific epitope on adenovirus hexon can be recognized by immunoblotting following SDS-PAGE provided that samples are not boiled prior to electrophoresis. Under these conditions, multiple bands corresponding to native forms of hexon were detected above the position of the denatured hexon monomer. Among representative serotypes of subgroups A, B and F, two predominant bands, corresponding to hexon trimers and 'group of nine' hexons (GONs), were routinely observed. In contrast, higher order structures, in addition to trimers and GONs, were characteristic of subgroup C adenoviruses. These serotypic differences in stability of hexon structures may reflect differences in protein-protein interactions within the corresponding virions.