Characterization of a hormonogenic domain from human thyroglobulin.
A polypeptide domain of molecular mass near 22 kDa was purified from CNBr-digest of iodine poor human thyroglobulin (hTgb). This fragment represents the N-terminal part of the hTgb molecule and consequently contains the preferential hormonogenic tyrosine 'acceptor' of the protein. This fragment could correspond to the non-iodinated and unreduced form of the thyroxinyl-containing 26 kDa peptide previously purified from reduced and iodinated hTgb. This 22 kDa fragment is capable by itself, i.e. independently of the remaining hTgb molecule, of synthesizing thyroxine with a high efficiency after in vitro iodination. Its study should constitute a valuable way to identify at least one of the hormonogenic tyrosine 'donor' residues of hTgb.
D000595:Amino Acid Sequence; D003488:Cyanogen Bromide; D006801:Humans; D007454:Iodides / Q000378:metabolism; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism*; D013954:Thyroglobulin / Q000032:analysis*; D013974:Thyroxine / Q000096:biosynthesis
D007454:Iodides; D010446:Peptide Fragments; D013954:Thyroglobulin; D003488:Cyanogen Bromide; D013974:Thyroxine