Background and purpose: Measurement of thyroid stimulating hormone (TSH), usually through RIA and ELISA tests, is very useful for the diagnosis of thyroid disorders. Considering the structural similarity between alpha chain of TSH and the three glycoprotein hormones of luteinizing hormone, follicle stimulating hormone, and chorionic gonadotropin (CG), in this study, we aimed to examine the produced beta-subunit of TSH (TSHβ) in terms of antigenicity.
Materials and methods: In this study, human TSHβ gene was synthesized using recombinant method. The cloning, expression, and purification were performed in Escherichia coli. Thereafter, antigenicity of the protein against antibodies against animal monoclonal TSH was evaluated using
Western Blot technique.
Results: TSHβ gene was cloned and expressed correctly in the bacterial host. The purified protein reacted with the specific antibody in Western Blot.
Conclusion: Although recombinant TSHβ protein is different from the natural protein in some respects such as structure and spatial shape, it had acceptable antigenicity. On the other hand, it seems that this protein, due to having more TSH epitopes, can be applied in diagnostic kits to enahance the
specificity of these tests.