title: [The inherent fluorescence of thyroglobulin].
abstract: Properties of tryptophane and tyrosine fluorescence of intact and iodinated thyroglobulin from normal human thyroid and nodular euthyroid goiter were studied. It has been shown that practically all (95%) tryptophane residues in "normal" thyroglobulin are in the inner regions of the globule. In "pathological" thyroglobulin in the regions inaccessible for water there are located only 68% of trypthophanyls. After iodination only in "pathological" thyroglobulin redistribution of tryptophan residues takes place on the surface and inside the globule. For bovine thyroglobulin shifts of tryptophane fluorescence spectra to the long wave region were observed, as well as a fall of the quantum yield at pH below 5 and above 11, which is in accord with acid and alkaline denaturation. A conformation transition was observed in the pH region 6--7 which is accompanied by a change in the efficiency of excitation energy transfer from tryptophan to iodoamino acids.
mesh_terms: D000818:Animals; D002417:Cattle; D006044:Goiter, Nodular / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013954:Thyroglobulin / Q000302:isolation & purification; D013961:Thyroid Gland / Q000032:analysis
chemical_list: D013954:Thyroglobulin
vernacular_title: Issledovanie sobstvennoĭ fluorestsentsii tireoglobulina.