title: Thyroid hormone contamination in crystalline diiodotyrosine.
abstract: Crystalline preparations of diiodotyrosine contain trace quantities of thyroxine that can be detected by several competitive radioassays and by chromatography on Sephadex. Spontaneous coupling of diiodotyrosine to thyroxine during iodination of tyrosine and coprecipitation of hormone with diiodotyrosine crystals are likely explanations for the trace contamination. We discuss the significance of these findings in relation to studies on the biosynthesis of thyroxine.
mesh_terms: D004105:Diiodotyrosine; D004340:Drug Contamination; D013974:Thyroxine / Q000096:biosynthesis
chemical_list: D004105:Diiodotyrosine; D013974:Thyroxine