Both TSH and thyroid-stimulating antibody of Graves' disease bind to an Mr 197,000 holoreceptor.

Human and porcine thyroid plasma membranes were submitted to sodium-dodecyl sulphate polyacrylamide gel electrophoresis in the absence and presence of reductant and electrotransferred onto nitrocellulose paper. Native bovine TSH, IgG from all 10 patients with active Graves's disease tested, as well as rabbit anti-bTSH anti-idiotypic antibody were found to bind to a single Mr approximately 197,000 band present only in non-reduced gels. We conclude that TSH and Graves' IgG bind to the TSH holoreceptor.