Human thyroid peroxidase: autoantibody recognition depends on the natural conformation

Thyroid peroxidase (TPO) purified from human thyroid glands was used to study the correlation relation between natural conformation and its ability for binding of autoantibodies in sera from patients with autoimmune lymphocytic thyroiditis (Hashimoto's thyroiditis). Treatment with heat (60 degrees C), urea, sodium dodecylsulfate (SDS), and dithiothreitol (DTT) decreased the autoantigenicity of TPO on average by 73.3%, 74.1%, 86.3%, and 91.8% measured by enzyme-linked immunosorbent assay (ELISA), respectively. These data demonstrate, that the binding of the majority of autoantibodies to human TPO depends on its natural conformation and modification.